East Asian countries, such as China, Japan and South Korea, are major importers in the international oil market. Therefore, oil import security is critical to sustainable economic development in these countries. This paper uses a modified two-stage DEA-like model to investigate the impact of the Organization of Petroleum Exporting Countries (OPEC) on oil import security in the East Asian region over time. Specifically, three dimensional variables were introduced to the model: the OPEC internal dimension, the OPEC and Asian country interaction dimension, and the international external dimension. The empirical results show a substantial difference between China and the other two countries in terms of these dimensions. Although the impact of OPEC on China's oil security has increased over time, its impact on Japan has declined. Political uncertainty in OPEC countries and oil price volatility are the major issues for China, whereas cost is the key area of concern for Japan. South Korea's concerns are less clear. The results of this study lay an important foundation for discussing policy issues involved in regional cooperation, integration and sustainable growth in the East Asian region.