A total of 47 plant extracts representing 132 genera and 172 species of plants distributed over 59 families were collected from various parts of Nigeria. The plant extracts were screened for the presence of alkaloids, saponins, tannins, phlobatannins and anthraquinones. The number of positive tests obtained was 176 (32.18%) for alkaloids, 242 (44.24%) for saponins, and 435 (79.52) for tannins. A few were positive for phlobatannins and anthraquinones.