Human spermatozoa were incubated with gossypol acetic acid (100 pg/ 1 x lo6 spermatozoa/ml) at 37" C for 30 min. The drug treatment inhibited the spermatozoal motility significantly. Washing of the spermatozoa, after gossypol treatment, did not effect their motility. A partial revival in the motility of the spermatozoa was observed when gossypol treated spermatozoa were incubated, after washing, with motility stimulating factors, e.g. theophylline, dibutyrylcAMP and Kallikrein.