Varicocele is defined as dilated and twisted veins of the pampiniform plexus in the spermatic cord. It is the most common cause of male infertility. There are various medical and surgical procedures for the treatment of this disease. This study was aimed to compare the effects of oral administration of L-Carnitine and varicocelectomy on spermogram parameters. This study was conducted as a double blind clinical trial without randomization. Inclusion criteria were, all married infertile men with varicocele. Patients chose their treatment personally and spermogram was carried out for all patients before and after the third and sixth months of treatment. Then, the sperm parameters of the two groups were compared using repeated measures ANOVA. In our study, trend of sperm count in the surgery group changed from 22 to 28.61 million (vs 34.6 to 45.37 in L-Carnitine group), motility changed from 21.74 to 35.38 percent (vs 33.9 to 47.48 in L-Carnitine group), normal sperm morphology changed from 46.25 to 60 percent (vs 56.61 to 69.7 in L-Carnitine group) and volume of semen changed from 3.5 to 4.17 cc (vs 2.95 to 4.33 in L-Carnitine group). These values were not statistically different between the two groups. Based on the results of this study, we can say that medicinal treatment by administration of oral L-Carnitine is as effective as varicocelectomy in improving semen parameters and can be used as an alternative to surgery for varicocele grade II.