With a population of 600 million, ASEAN is considered to be one of the most diverse regions in the world. It is also one of the world's fastest growing regions. ASEAN's aim is to evolve into an integrated economic community by 2015. Crucial to achieving this ambitious target is cooperation in infrastructure development for physical connectivity, particularly in cross-border infrastructure. This paper provides an overview of the quantity and quality of existing infrastructure in ASEAN member countries, as well as ASEAN initiatives in cross-border infrastructure development in the energy, transportation and communication sectors. It examines the role of, and need for, infrastructure development towards an integrated ASEAN, and discusses associated issues and challenges. This paper also provides estimates of ASEAN infrastructure financing requirements up to 2015, and identifies ways to meet this demand, especially in view of the current global economic crisis. The paper concludes with a discussion on the need to enhance ASEAN infrastructure cooperation towards achieving the ultimate vision of Asia-wide connectivity and integration.