Varicocele is currently the most common irregularity identified in males that is associated with impaired spermatogenesis. It primarily presents in the form of decreased sperm count and motility, abnormal morphology, and significantly increased sperm DNA fragmentation. Several studies have shown that surgical repair improves semen parameters and increases the odds of spontaneous pregnancy. However the exact effect of surgical repair treatment remains controversial. Therefore, the aim of our study was to evaluate the effectiveness of microsurgical repair by comparing common semen parameters and sperm DNA fragmentation index (DFI). We evaluated infertile men (n = 19) who underwent microsurgical subinguinal varicocelectomy for treatment of clinical varicocele before and 3 months after surgery. Normozoospermic men (n = 19) were considered as the normal control group. Semen parameters improved significantly after surgery when compared with that before surgery, but still significant differences with the normal control group were observed. In comparison, sperm DNA integrity improved significantly after surgery (percentage DFI decreased from 28.4 ± 15.6% before surgery to 22.4 ± 12.9%, at 3 months post surgery) to similar levels as the normal control group. These results suggest that microsurgical repair may be considered as a treatment option in infertile men with palpable varicocele.