Semen samples collected from 47 Nigerian patients attending infertility clinics were analyzed for zinc, copper, magnesium and enzyme alkaline phosphatase. The results were correlated with the semen quality, which was assessed by the biophysical characteristics of the spermatozoa. Results of the analysis divided the patients into three groups: 9 fertile patients, 9 patients of doubtful fertility and 29 patients with severely pathologic ejaculates. The biophysical differences among the three groups were significant. Biochemical studies of the specimens did not, however, demonstrate enough significant variation to show that the semen values of the three groups could be used as an index of male fertility.