This prospective, double-blind controlled trial was conducted to determine the effect of silicone gel in the reduction of postoperative scar after bilateral inguinal varicocelectomy. Thirty-four patients were enrolled in this study; the right-side inguinal scar was treated with silicone gel and petroleum jelly (Vaseline) applied on the left side as a placebo for 60 consecutive days. Scars were evaluated using the Vancouver Scar Scale, pruritus and pain. The result of this study showed that silicone gel was effective in the regression of postoperative scar after microscopic inguinal varicocelectomy in five key parameters, including vascularity, pigmentation, pliability, height and pruritus in comparison to placebo application (p < 0.05), while its effect on pain was insignificant (p > 0.05). The study showed that silicone gel had a considerable effect in the treatment and management of postoperative scar management. Varicocele is a condition that is considered the most common cause of male infertility. While microscopic inguinal varicocelectomy is considered a gold standard in the management of varicocele, its postoperative complications, such as scar formation remain a concern. Recent studies show that silicone gel can be an effective non-invasive treatment for scar regression. Accordingly, we designed this trial to evaluate the effect of silicone gel after microscopic inguinal surgery. A prospective double-blind controlled trial was conducted on 34 patients who had microscopic bilateral inguinal varicocelectomy (their age ranged from 19 to 41) at Namazi hospital. Two weeks after surgery, each patient received two identical tubes for application on the scars, the first tube containing silicone gel and the second one dispensed with petroleum jelly (Vaseline). The right side was treated with silicone gel, and the left side with Vaseline twice daily for 60 days. Then, patients were evaluated three times: firstly 2 weeks after surgical repair; second appointment after 2 months and third one after 6 months after surgery, using the Vancouver Scar Scale, pruritus and pain score. The collected data were analysed in SPSS 26, using the chi-square and Mann–Whitney U tests. The significance level was defined at p < 0.05. This study showed that silicone gel was highly effective in scar parameters, including pliability, height, vascularity pruritic and pigmentation. However, its effect on pain reduction was not significant (p > 0.05). The results of the study indicated that silicone gel effectively improved scar characteristics following microscopic inguinal varicocelectomy, while its efficacy against pain was not significant.