© 2015, The International Urogynecological Association. Introduction and hypothesis: The objective was to compare midurethral sling (MUS) urinary outcomes in women with stress urinary incontinence (SUI) only versus mixed UI (MUI). Methods: This was a retrospective cohort study of women who underwent primary MUS surgery for SUI. MUI was defined as at least “moderately” bothersome urgency and stress incontinence on the Urinary Distress Inventory (UDI-6) subscale of the Pelvic Floor Distress Inventory-20 (PFDI-20). The primary outcome was SUI cure defined by a response of “no,” “not at all,” or “somewhat” bothersome SUI on both of the two UDI-6 stress subscale items. Symptom impact was assessed using the Urinary Impact Questionnaire (UIQ-7). Multivariable models assessed the effect of MUI on SUI outcomes. Results: One thousand one hundred and ninety-one primary MUS procedures were reviewed. Seven hundred and fifteen out of 1,191 (60 %) questionnaires were returned and 534 out of 715 (75 %) had completed baseline and follow-up questionnaires. Mean (±SD) follow-up time was 35 ± 15 months. Women with MUI had a higher (worse) baseline total score on the UDI-6 (p ≤ 0.001). A lower proportion of women with MUI had SUI success compared with the SUI only group (64 vs 84.5 %, p < 0.001). On multivariable analyses, women in the MUI group were at an increased risk of SUI failure (OR 2.5, 95 % CI 1.6, 4.0), but greater improvements in UDI-6 (−31.6 ± 30.6 vs −15.5 ± 25.1), and UIQ-7 scores (−21.7 ± 35.3 vs −15.1 ± 28.2) compared with women with SUI only (all p < 0.02). Conclusions: Women with MUI are at an increased risk of SUI failure after MUS compared with women with SUI only, but experience greater overall improvement in the impact of urinary symptoms on the quality of life.