Blood and semen samples obtained from 24 "normal" volunteers were analyzed for 16 different biochemical parameters. These included: Ca, Mg, K, Na, Zn, Cl, P, glycerolphosphorylcholine (GPC), carnitine, fructose, uric acid, prostatic acid phosphatase, alkaline phosphatase, glutamic oxaloacetic transaminase (SGOT), lactic dehydrogenase (LDH), and glutamic pyruvate transaminase (SGPT). With the exception of uric acid, all the biochemical constituents in seminal plasma were either significantly higher (p less than 0.001, except alkaline phosphatase which was significant at p less than 0.05) or significantly lower (p less than 0.001) than in blood serum. Further, potassium (r = 0.51); carnitine (r = 0.54); and SGOT (r = 0.70) showed a significant direct relationship in blood and seminal plasma.