Objective. To compare the prevalence of anal incontinence and dyspareunia in women with or without obstetric sphincter injury after standardizing the suture technique. Design. Retrospective case–control study. Setting. Regional hospital, Sweden. Population. 305 women with an obstetric sphincter injury and 297 women with spontaneous vaginal delivery. Methods. In order to standardize and improve the repairing skills of sphincter injuries, collaboration between obstetricians and colorectal surgeons was begun in 2000. Inner and external sphincters were repaired in two layers with continuous monofilament polidioxane sutures. The participating women received a questionnaire with validated questions on anal incontinence, dyspareunia and quality of life. The follow-up time was 15 months to 8 years. Main outcome measures. Anal incontinence, dyspareunia and quality of life. Results. Of the sphincter group, 72% returned the questionnaire, as did 67% in the control group. Significantly more women in the sphincter group suffered from incontinence of flatus and loose stool compared to controls (p < 0.05). There was no significant difference of incontinence of solid stool, soiling, or fecal urgency between the groups. The quality of life questions showed no significant difference between the groups. In the sphincter group, there was significantly more superficial coital pain compared to controls (p= 0.02). Significantly more women with complete sphincter injury reported anal incontinence than women with a partial sphincter injury. Conclusion. In spite of increased rate of anal incontinence and dyspareunia after anal sphincter rupture, there was no statistically significant reduction in the women's quality of life.