The article explores how joining the ASEAN Free Trade Area (AFTA) affects Cambodia, the Lao PDR, Myanmar, and Vietnam. By reducing tariffs with ASEAN countries, these new members benefit economically, but some trade diversion occurs. AFTA's protection rate commitments are a good start for broader trade reforms. Challenges like lower tariff revenues in Cambodia and harm to local industries in Vietnam need to be addressed. Joining AFTA is a crucial step towards successful development and reducing poverty.