The specific activities of some purine metabolism enzymes [Adenosine deaminase (ADA), AMP-deaminase, 5`-nucleotidase (5`- NT) and xanthine oxidase (the two forms: xanthine oxidase (XO) and xanthine dehydrogenase (XDH)], were measured in sera of control (n=45) and patients with prostate cancer (n=47).Sera ADA and AMPdeaminase specific activities in prostate cancer were significantly decreased (p<0.001) when compared with control group. By contrast there was significant increase (p<0.001) in 5`-NT specific activity observed in sera of prostate cancer. The activities of xanthine oxidase (XO) (the oxidase and the dehydrogenase activities) were the results revealed no detectable oxidase activities of XO in sera of prostate cancer. Where as, the dehydrogenase activity of this enzyme show significant decrease (p<0.001) in comparism to control group. Two forms and three forms of ADA were found in sera of control andprostate cancer patients respectively as judged by polyacrylamide gel electrophoresis .Three forms of 5`-NT were found in sera of prostate cancer patients and control. One forms of AMP-deaminase was detected in the sera of control and prostate cancer patients. ADA, AMPdeaminase, 5`-NT and (XO, XDH) enzymes may be used as a biochemical markers in prostate cancer patients to help the early diagnosis.