Knowledge on sexual complaints and time to sexual resumption after obstetric anal sphincter injury (OASI) is scarce. The aim of the study was to investigate self-reported sexual activity and coital problems 1year postpartum in relation to perineal trauma, in addition to delivery mode. Among 2,846 women recruited during pregnancy, all women who delivered with OASI (n = 42, all third-degree perineal tears), in addition to 20 randomly selected controls per OASI case, a total of 882 women, were sent a self-administered questionnaire addressing time to coital resumption after delivery and potential coital difficulty 1year postpartum. By 8weeks, half of the 561 responders (51.4%) had resumed intercourse, increasing to 75.2% by 12weeks and 94.7% 1year postpartum. In multivariate regression analysis OASI was the strongest predictor for postponed coital onset, defined as after 8weeks (aOR 5.52, CI 1.59-19.16). OASI was also the only significant predictor for dyspareunia 1year after delivery (aOR 3.57, CI 1.39-9.19). Episiotomy was neither a risk factor for postponed coital onset nor for dyspareunia. There were no differences between episiotomy and second-degree laceration injury groups regarding postponed coital onset (p = 0.45) or dyspareunia (p = 0.67) 1year postpartum. Obstetric anal sphincter injury was a strong and independent predictor for both postponed coital resumption after delivery and for dyspareunia 1year postpartum, whereas episiotomy and spontaneous second-degree lacerations were not. Our main finding of affected sexual activity after OASI further supports the need to reduce the rates of this obstetric injury to a minimum.