This article examines the effect of Japan's official development assistance (ODA) over 10 years that proposed to facilitate environmental conservation in developing countries. Special emphasis is given to ODA disbursements in the energy sector to evaluate whether Japan's foreign aid has shifted its policy toward more environmentally sound goals. The article finds that despite its articulated premise, Japan's ODA for the energy sector has favored environmentally problematic projects, that is, those based on fossil fuels and larger scale (10 megawatt or larger) hydropower. Similar to patterns in the early 1990s, environmentally friendly projects have received little attention. It is not surprising that the expected amount of greenhouse gas emissions from Japan's ODA-supported energy projects appears substantial.