Environmental impact assessment (EIA) is a major tool that has been adopted worldwide as a control measure to protect the environment and by extension human health from the harmful effect of human activities. The aim of this paper is to provide review of environmental impact assessment (EIA) process in Nigeria and compare with International best practice. In this paper the researchers have presented the review of the historical development of environmental impact assessment in the world, the birth, the legal framework, processes, procedures and factors hindering the effectiveness of EIA practice in Nigeria, the international basic and Operating principles of EIA best practice. Factors that are hindering the effectiveness of EIA practice in Nigeria as identified from relevant literatures during the review include; emphasis on economic benefits at the detriment of environmental concern, inadequate public involvement /participation, reduction of EIA to mere literature review exercise, lack of transparency during scoping, absence of an independent body/authority for EIA review and quality assessment, lack of community awareness on their role during EIA study and lack of effective monitoring during project implementation. It is concluded that EIA remains a veritable tool for the protection of the environment and therefore it is recommended that project proponents including governments, NGOs, private developers and the general public should not see EIA as a mere project approval requirements but a necessary and major tool to protect the environment, public health and to ensure sustainable development.