To estimate the duration of time required following varicocelectomy to wait for the improvements of semen parameters. Therefore, we characterized the changes with the time in sperm parameters in men after varicocelectomy.In this prospective cohort study we included consecutively observed men who underwent varicocelectomy between September 2017 and September 2018 in a referral academic hospital. Clinical data of the patients, as well as their semen parameters, were measured before surgery and at 3 and 6 months afterward.In this study, a total of 100 men with average age of 29.5 ± 6.2 years were included. Mean sperm concentration and sperm motility significantly improved by 3 (p < 0.05), but not by 6 months following varicocelectomy. The semen volume and sperm with normal morphology were the same before and after surgery (p > 0.05). There was no statistically significant difference in the improvement of semen parameters when comparing 6 months to 3 months postoperatively (p > 0.05).Sperm parameters (concentration and motility) improve by 3 months after varicocelectomy without further improvements. Consequently, physicians should decide quickly after 3-month of varicocelectomy if surgery has been not helpful and then plan other therapies, like assisted reproductive technology (ART) for managing infertility in couples.