This year, the Association of Southeast Asian Nations (ASEAN) celebrates the 50th anniversary of the signing of the Bangkok Declaration. The jubilee is an opportunity to sum up the organisation’s achivements and draft plans for future development. This article aims at analysing integration within ASEAN from the perspective of the CLMV states (Cambodia, Laos, Myanmar, Vietnam) as the newest members of the community. The research focusses on whether or not it is justified to perceive ASEAN as a "two-tier organisation" and if developmental differences between the two groups of members exert a significant influence on the efficiency of the integration process. The integration in examined in three crucial aspects compatible with ASEAN's three-pillar division: politics and security, the economy and socio-cultural cooperation.