The leading cause of male infertility is the presence of varicocele. Recently, selective spermatic vein embolization during spermatic venography has afforded a simple, nonoperative treatment. In this study, liquid crystal contact thermography was employed before spermatic venography and after embolization or surgery. Pretreatment thermographic results were in agreement with venography in 15 of 17 cases as 13 were considered positive and two negative by both methods. Thermography further served to document objectively the immediate physiologic effectiveness of either therapy in controlling spermatic vein reflux into the pampiniform plexus. It therefore provides a noninvasive means of evaluating treatment success or recurrence at an early stage. Preliminary thermographic evidence indicates that embolization is a highly effective treatment of reflux. Thermography can also function as a useful, noninvasive screening technique to aid in selecting patients for spermatic venography and embolization therapy.