Objectives: This study aims to investigate the impact of anterior cruciate ligament (ACL) injury and its reconstruction on men's sexual functions. Patients and methods: Between February 2016 and November 2019, a total of 27 sexually active male patients (mean age: 33.7±4.3 years; range, 26 to 40 years) who were operated for ACL injury at least six months after trauma were retrospectively analyzed. Erectile function was assessed using the International Index of Erectile Function questionnaire (IIEF) and knee function was evaluated by using the International Knee Documentation Committee (IKDC) Scoring System, Lysholm Knee Scoring Scale, and Tegner Activity Score. Sexual and functional questionnaires were applied to evaluate three different periods retrospectively. These periods were as follows: the period before an ACL injury (Period I); the period in which the patient suffered from an ACL injury, but not operated (Period II), and the period after the ACL reconstruction (Period III). Results: There was a statistically significant difference in the comparison of knee function scores according to three different periods. Sexual function scores were significantly different between Periods I and II, and between Periods I and III. However, although the IIEF value was higher in Period III than in Period II, no statistically significant difference was observed. A moderate correlation was found between the sexual functional scores of IIEF and IKDC scores. Conclusion: Our study results suggest that ACL injury affects sexual functions adversely. The change in sexual functions after ACL surgery depends on the success of surgery. While deciding on the treatment of ACL injury, the patient's sexual life should be questioned along with his expectations.