Man has increasingly affected the succession of the rainforest ecosystem in Nigeria through various activities connected with his settlement on land. Consequently, little of the Nigerian rainforest ecosystem has remained undisturbed, and extensive areas of original climax vegetation no longer exist in the country. The paper reviews some of the major areas of man's impact on this forest ecosystem. Specifically, it examines me issues of pollution, surface mining, road building, industrialisation and urbanisation. Brief attention is paid to cultural eutrophication, which has been attributed largely to the increase of nitrates and phosphorus added to the water from many sources; this is particularly noticeable in the aquatic sectors of the Nigerian forest ecosystem. Surface mining in Nigeria (which is essentially area strip-mining) causes dereliction of the land, and to combat its undesirable effects, it is suggested that extensive reclamation regulations should be formulated and enforced to cover such issues as slope reduction, back-filling, levelling, revegetation and burying of toxic materials. Industrialisation and urbanisation involve total forest removal, the consequences of which include flooding and soil erosion. Similar consequences arise from road building in the country, and the paper stresses the need to make these operations more rational, not by discontinuing the work but by modifying it so as to save the Nigerian rainforests from total destruction. Accordingly, careful management of the forests is required, whilst continuing the attempt to improve the status of the population. To achieve this desired objective, the paper emphasises the need for a comprehensive national land-use policy, including careful management of the forests. Such an approach would ensure that Nigeria does not indulge in the costly option of improving the circumstances of one generation at the expense of the next.