This article is aimed examining the relations between the Republic of Korea (ROK) and the Association of Southeast Asian Nations (ASEAN) over the past two decades since the establishment of ROK and ASEAN dialogue relations in 1989. With regard to the ROK’s perspective, ASEAN is not only a significant friend in ensuring peace and security on the Korean peninsula, but a major economic partner actively engaged in trade, investment, and construction. The ROK and ASEAN have frequently exchanged human resources, recording 4 million mutual visits per year. In particular, Korea’s enhanced brand image, due to the Hallyu (Korean Wave) within the ASEAN region, has enabled ASEAN’s preference for Korean mobile phones, electronic products, and durable goods to stand eminent. Over the past two decades, ASEAN-ROK relations have developed since the early establishment period and negotiations for a permanent consultative mechanism, followed by cooperation expansion and deepening stages. More importantly, in commemoration of the 20th anniversary of ASEAN-ROK dialogue relations, at the ASEAN-ROK Commemorative Summit in Jeju Island in June 2010, the ROK government initiated plans for development cooperation, low-carbon green growth, and cultural and human resources exchanges, which are the three main policies of the ROK government’s diplomacy toward ASEAN. In addition, at Hanoi ASEAN-ROK Summit in October 2010, it is noteworthy that the existing ASEAN-ROK comprehensive relations had been elevated to a strategic partnership. At present, ASEAN-ROK relations have been institutionalized, through 24 cooperation mechanism meetings on issues ranging from politics/security, economy, Information and Communication Technology (ICT) to transportation, the singing of the ASEAN-ROK FTA, and the establishment of the ASEAN-ROK Center. A representative mission to ASEAN in Jakarta is also planned for 2012. Following the Asian financial crisis in 1997, both the ROK and ASEAN have endeavored to expand cooperation at the East Asia level. Furthermore, the establishment of the ASEAN+3 has served as the most institutionalized mechanism in East Asia. The expansion of the East Asia Summit (EAS) by the accessionof the US and Russia has ushered in a new era in the history of the East Asia regional cooperation. At such time, a new vision would be necessary to guide the future of East Asia. In this regard, the ROK government will take the lead in submitting the EAVGII report to the ASEAN+3 Summit in 2012, successive to the 2001 EAVG report.