From 1985 to 1996, Thailand's economy grew at an average of over 9% per year, the highest economic growth rate of any country at the time. Inflation was kept reasonably low within a range of 3.4–5.7%. The baht was pegged at 25 to the U.S. dollar.

The Chinese currency, the renminbi (RMB), had been pegged in 1994 to the U.S. dollar at a ratio of 8.3 RMB to the dollar.

The banking sector was burdened with non-performing loans as its large corporations were funding aggressive expansions. During that time, there was a haste to build great conglomerates to compete on the world stage. Many businesses ultimately failed to ensure returns and profitability. The chaebol, South Korean conglomerates, simply absorbed more and more capital investment. Eventually, excess debt led to major failures and takeovers. The Hanbo scandal of early 1997 exposed South Koreas economic weaknesses and corruption problems to the international financial community.

Many businesses collapsed, and as a consequence, millions of people fell below the poverty line in 1997–1998. Indonesia, South Korea and Thailand were the countries most affected by the crisis.

Having largely kept itself above the fray throughout 1997–1998, there was heavy speculation in the Western press that China would soon be forced to devalue its currency to protect the competitiveness of its exports vis-a-vis those of the ASEAN nations, whose exports became cheaper relative to China's.

In May 1997, the Bangko Sentral ng Pilipinas (literally "Central Bank of the Philippines"), the country's central bank, raised interest rates by 1.75 percentage points and again by 2 points on 19 June.

On 14 May and 15 May 1997, the Thai baht was hit by massive speculative attacks.

In June 1997, Indonesia seemed far from crisis. Unlike Thailand, Indonesia had low inflation, a trade surplus of more than $900 million, huge foreign exchange reserves of more than $20 billion, and a good banking sector. But a large number of Indonesian corporations had been borrowing in U.S. dollars. During the preceding years, as the rupiah had strengthened respective to the dollar, this practice had worked well for these corporations; their effective levels of debt and financing costs had decreased as the local currency's value rose.

On 30 June 1997, Prime Minister Chavalit Yongchaiyudh said that he would not devalue the baht.

Later that year, in July, South Korea's third-largest car maker, Kia Motors, asked for emergency loans. The domino effect of collapsing large South Korean companies drove the interest rates up and international investors away.

In July 1997, within days of the Thai baht devaluation, the Malaysian ringgit was heavily traded by speculators. The overnight rate jumped from under 8% to over 40%.

In July 1997, when Thailand float the baht, Indonesia's monetary authorities widened the rupiah currency trading band from 8% to 12%. The rupiah suddenly came under severe attack in August.

Thailand triggered the crisis on 2 July and on 3 July, the Bangko Sentral intervened to defend the peso, raising the overnight rate from 15% to 32% at the onset of the Asian crisis in mid-July 1997.

Thailand lacked the foreign reserves to support the USD–Baht currency peg, and the Thai government was eventually forced to float the Baht, on 2 July 1997, allowing the value of the Baht to be set by the currency market. This caused a chain reaction of events, eventually culminating into a region-wide crisis.

The HKMA and Donald Tsang, then the Financial Secretary, declared war on speculators. The Government ended up buying approximately HK$120 billion (US$15 billion) worth of shares in various companies, and became the largest shareholder of some of those companies (e.g., the government owned 10% of HSBC) at the end of August, when hostilities ended with the closing of the August Hang Seng Index futures contract.

On 11 August 1997, the IMF unveiled a rescue package for Thailand with more than $17 billion, subject to conditions such as passing laws relating to bankruptcy (reorganizing and restructuring) procedures and establishing strong regulation frameworks for banks and other financial institutions.

On 14 August 1997, the managed floating exchange regime was replaced by a free-floating exchange rate arrangement. The rupiah dropped further. The IMF came forward with a rescue package of $23 billion, but the rupiah was sinking further amid fears over corporate debts, massive selling of rupiah, and strong demand for dollars.

The IMF approved on 20 August 1997, another bailout package of $2.9 billion.

The rupiah and the Jakarta Stock Exchange touched a historic low in September. Moody's eventually downgraded Indonesia's long-term debt to "junk bond".

In October 1997, the Hong Kong dollar, which had been pegged at 7.8 to the U.S. dollar since 1983, came under speculative pressure because Hong Kong's inflation rate had been significantly higher than the United States' for years.

Stock markets became more and more volatile; between 20 and 23 October the Hang Seng Index dropped 23%.

The Hong Kong Monetary Authority then promised to protect the currency. On 23 October 1997, it raised overnight interest rates from 8% to 23%, and at one point to '280%'.

On 27 October 1997, the Dow Jones industrial plunged 554 points or 7.2%, amid ongoing worries about the Asian economies.

The crisis led to a drop in consumer and spending confidence (see 27 October 1997 mini-crash). Indirect effects included the dot-com bubble, and years later the housing bubble and the subprime mortgage crisis.

The Seoul stock exchange fell by 4% on 7 November 1997.

On 8 November, it plunged by 7%, its biggest one-day drop to that date.

In the wake of the Asian market downturn, Moody's lowered the credit rating of South Korea from A1 to A3, on 28 November 1997, and downgraded again to B2 on 11 December.

In 1998, Hyundai Motor Company took over Kia Motors.

Samsung Motors' $5 billion venture was dissolved due to the crisis, and eventually Daewoo Motors was sold to the American company General Motors (GM).

In 1998, the output of the real economy declined plunging the country into its first recession for many years. The construction sector contracted 23.5%, manufacturing shrunk 9% and the agriculture sector 5.9%. Overall, the country's gross domestic product plunged 6.2% in 1998.

Unlike investments of many of the Southeast Asian nations, almost all of China's foreign investment took the form of factories on the ground rather than securities, which insulated the country from rapid capital flight. While China was unaffected by the crisis compared to Southeast Asia and South Korea, GDP growth slowed sharply in 1998 and 1999, calling attention to structural problems within its economy.

The baht devalued swiftly and lost more than half of its value. The baht reached its lowest point of 56 units to the U.S. dollar in January 1998. The Thai stock market dropped 75%. Finance One, the largest Thai finance company until then, collapsed.

The rate plunged to over 11,000 rupiah to 1 U.S. dollar on 9 January 1998, with spot rates over 14,000 during 23–26 January and trading again over 14,000 for about six weeks during June–July 1998.

In February 1998, President Suharto sacked Bank Indonesia Governor J. Soedradjad Djiwandono, but this proved insufficient. Amidst widespread rioting in May 1998, Suharto resigned under public pressure and Vice President B. J. Habibie replaced him.

On 31 December 1998, the rate was almost exactly 8,000 to 1 U.S. dollar. Indonesia lost 13.5% of its GDP that year.

In 1999, the Government started selling those shares by launching the Tracker Fund of Hong Kong, making a profit of about HK$30 billion (US$4 billion).

The Philippine GDP contracted by 0.6% during the worst part of the crisis, but grew by 3% by 2001, despite scandals of the administration of Joseph Estrada in 2001, most notably the "jueteng" scandal, causing the PSE Composite Index, the main index of the Philippine Stock Exchange, to fall to 1,000 points from a high of 3,448 points in 1997.

By 2001, Thailand's economy had recovered.

The peso dropped from 26 pesos per dollar at the start of the crisis to 46.50 pesos in early 1998 to 53 pesos as in July 2001.

The increasing tax revenues allowed the country to balance its budget and repay its debts to the IMF in 2003, four years ahead of schedule.

Compared to the 1997 current account, by 2005, Malaysia was estimated to have a $14.06 billion surplus.

In 2005 the last of the crisis measures were removed as taken off the fixed exchange system. But unlike the pre-crisis days, it did not appear to be a free float, but a managed float, like the Singapore dollar.

The Thai baht continued to appreciate to 29 Baht to the U.S. dollar in October 2010.