BACKGROUND: The ideal treatment method for pilonidal sinus has always been a matter of debate. Although primary closure or various flap applications offer shorter wound healing times, their infection rates are very high. Secondary recovery involves long recovery period. The aim of this study is to investigate the effects of gentamicin-impregnated collagen sponge on wound healing and infection in patients undergoing marsupialization. PATIENTS AND METHODS: Fifty patients were included in the study. Twenty-five patients in control group (Group 1) underwent excision and marsupialization. Gentamicin-impregnated collagen sponge was used postoperatively in twentyfive patients in group 2. Three-dimensional wound measurements were made on the 0.7 and 15th days and recorded. RESULTS: No significant difference was observed between the groups in terms of development of hemorrhage and infection. Excessive granulation was detected in five patients (two in group 1 and three in group 2). There was no significant difference between the groups with respect to this criterion. Full recovery times were 29.6 and 28.2 days respectively. No statistically significant difference was observed between the groups (p = 0.571). None of the patients developed recurrence at the end of the follow-up period of 6-30 months. CONCLUSION: In accordance with the results obtained in this randomized and controlled study, no significant difference was observed between gentamicin-impregnated collagen sponge group and control group with respect to development of infection, hemorrhage and wound healing times. Therefore, we do not recommend the use of gentamicin-impregnated collagen sponge after marsupialization.