Abstract: Efficiency is an important determinant for sustainability of modern business. The efficiency of the banking market is more governing especially in the developing countries because the role of the banking system is to support national development especially the economic growth. This study is to provide a general level of cost efficiency of the ASEAN banking market. The study applies a parametric methodology known as the Stochastic Frontier Analysis (SFA). In short, the study infer that the cost efficiency of the ASEAN banking is 71%. Further, the cost efficiency score for Brunei is 58%, Indonesia is 70%, Cambodia is 60%, Laos is 62%, Myanmar is 48%, Malaysia is 63%, Singapore is 80%, Thailand is 79%, Phillippines is 67% and finally Vietnam 69%. The study unveiled that Singapore and Thailand banking markets are on average the most efficient. However, Singapore is the most efficient banking market although the trend is downward.