The Association of Southeastern Asian Nations (ASEAN) was founded in 1967 primarily as a forum for discussing issues of mutual concern among neighboring Southeast Asian countries rather than as a trading union similar to the EEC. In part, this orientation was because, other than Singapore, most of the ASEAN countries had similar products, tending to make them more competitive than cooperative. Although trade relations among the ASEAN countries remained largely bilateral, there was some informal economic cooperation, including joint representations to foreign governments on economic issues of common concern. In 1989 the possibility of a more formalized economic entity was at least being considered by the ASEAN members.

In 1988 Malaysia was Singapore's largest ASEAN trading partner and third largest overall trading partner, after the United States and Japan. The Malaysian market was the single largest ASEAN destination for Singapore's exports and its second largest export market overall. In the late 1980s, Singapore established increasingly close economic and industrial ties with Malaysia's Johor state, which had served as Singapore's hinterland in colonial times. To alleviate its land shortage as well as its labor shortage and high labor costs, Singapore, began to transfer labor-intensive industries to sites across the causeway connecting it to Malaysia's southernmost state. Johor, in turn, hoped "economic twinning" with Singapore would boost its long-term development. By early 1987, there were 217 Singaporean companies or Singapore-based multinationals in Malaysia, having total investments of slightly more than S$200 million.

Singapore's much smaller markets with the other ASEAN countries also were growing. In 1989 Singapore recorded its highest growth in bilateral ASEAN trade with Thailand, which replaced Taiwan as its fifth largest trading partner. Intra-ASEAN trade generally might have been underestimated, partly because of the volume of informal trade, including smuggling, and partly because so much of it was controlled by the Chinese community in each country. Keeping business within the family, clan, or dialect group was a central Chinese business practice that persisted across national boundaries.

Data as of December 1989