For over three decades, environmental assessment (EA) has gained increasing international recognition as a means of ensuring sustainable development. In light of environmental challenges, Benin has endorsed the principle that a healthy environment is a human right. This concern is manifested by the creation of many institutions for managing environmental issues. But until today, environmental problems are still on the rise and getting worse day by day because of Benin’s limited experience in the field of EA. If EA is to be perceived as an instrument of sustainable development, it is important to take into account the achievements and the needs of the country in this field; because we cannot respond properly and adequately in the field of capacity strengthening in EA without first be familiar with what exists, what is fact, and what is needed. In this study, we address and analyze the status of existing resources in the field of EA in Benin with the purpose of identifying the needs for capacity strengthening to enhance environmental assessment effectiveness in the country. The detailed presentation of the results shows that the legislative and institutional resources are available and represent a strong element in the system of environmental management in Benin. However, there is still a room for improvements towards environmental governance before it becomes a solid system of decision supporting all sectors of intervention because the effective application of those laws and texts still constitute big challenges. Below are the main reasons that explain the particular situation: majority of the laws are put in force very late or taken without implementing decree at all; the organizational capabilities have large gaps; the absence of a mechanism for evaluating the needs for strengthening capacity for EA. Recommendations pinpointed three types of needs which must be filled to enhance the effectiveness of EA in Benin: upstream needs of the structure of EA; implementation and enforcement needs; and, maintenance and efficiency needs.