INTRODUCTION: This is a retrospective cohort study comparing the risk of treatment for postoperative urinary tract infection (UTI) in patients who receive short-term postoperative catheterization versus those who pass a void trial on the day of surgery after midurethral sling with or without concomitant pelvic surgery. MATERIALS AND METHODS: We compared two cohorts to determine our primary outcome: treatment for UTI, culture proven or empiric, within three weeks after surgery. RESULTS: 138 patients, were included in the study of which 80 (58%) received postoperative catheterization. The baseline characteristics of the catheterized and noncatheterized groups were similar except that the catheterized group had a lower mean body mass index (28 ± 5 vs 30 ± 5 kg/m(2); P = 0.01), were more likely to have undergone concomitant pelvic surgery (51% vs 20%; P < 0.01), had higher estimated blood loss (92 ± 87 vs 47 ± 49 mL; P < 0.01), and had longer operative times (108 ± 75 vs 62 ± 47 min; P < 0.01). Overall, 19.6% of the patients received treatment for UTI. Patients in the catheterized group were more likely to receive treatment for UTI (24/80 [30%] catheterized vs 3/58 [5%] noncatheterized; P < 0.01). This significant difference in treatment for UTI persisted when examining patients who underwent midurethral sling only without concomitant pelvic surgery (6/29 [20.7%] catheterized vs 1/38 [2.6%] noncatheterized; P = 0.04). In a logistic regression model adjusting for age, body mass index, concomitant surgery, and postoperative catheterization, only postoperative catheterization remained significantly associated with treatment for UTI (OR, 6.6; 95% confidence interval, 1.8-24.5; P < 0.01). CONCLUSIONS: Treatment for postoperative UTI is significantly higher in patients who receive short-term postoperative catheterization after midurethral sling with or without concomitant pelvic surgery.