During the period of Sep. 1981 to Feb. 1983, a program of measuring the blood gases and pH of 19 varicocele patients was taken. These patients were classified into 2 groups based upon their semen analyses; Group A consisted of 9 patients who demonstrated normal findings and group B consisted of 10 patients who demonstrated seminal stress pattern. The blood pH: $PO_2$ , and $PCO_2$ were measured in the internal spermatic vein and the radial vein of all the patients. The results obtained were as follows; 1. In Group A, no difference was detected in the value of the pH, $PO_2$ and $PCO_2$ between the internal spermatic vein and the radial vein. 2. In group B, a similar lack of difference in blood gases found between the internal spermatic vein and the radial vein. 3. The blood gases between the internal spermatic veins of Group A and B were compared. No difference was discovered between the 2 group also. It has been hypothesized that the pathogenesis of spermatogenic depression in patients with varicocele is testicular hypoxia due to low oxygen tension of the internal spermatic vein. However, our results do not bear out this proposed mechanism.