Résumé : Introduction: Endometriosis is a chronic and progressive condition of women of reproductive age. It is strongly associated with a significant reduction of quality of life (QOL) and sexual function. Aims: This study aims to objectively evaluate sexual function in women with deep infiltrating endometriosis (DIE) and to study the impact of endometriosis symptoms and type of lesion on patient's sexual function. Methods: This is a cross-sectional study in a tertiary care university hospital. It included 182 patients with preoperative clinical and ultrasound diagnosis of DIE who were referred to our center from 2008 to 2011. Main Outcome Measures: A sexual activity questionnaire, the Sexual Health Outcomes in Women Questionnaire (SHOW-Q) was used to collect data pertaining to satisfaction, orgasm, desire, and pelvic problem interference with sex. Short Form 36 (SF-36) was used to evaluate QOL. Demographic and clinical characteristics were assessed: age, body mass index, parity, ethnicity, postsecondary education, employment, smoking, history of surgical treatment, and hormonal contraception. Patients were asked about pain symptoms (dysmenorrhea, dyspareunia, dyschezia, chronic pelvic pain, and dysuria) using a visual analog scale. Results: The mean values obtained on the different scales of the SHOW-Q showed poor sexual function (mean SHOW-Q total score 56.38±22.74). Satisfaction was the dimension most affected (mean satisfaction score 55.66±34.55), followed by orgasm (mean orgasm score 56.90±33.77). We found a significant correlation between the SF-36 scores and the SHOW-Q scores (P<0.0001). Sexual dysfunction and deterioration of QOL seem to be correlated. Analyzing the impact of symptoms and lesions on sexual function, we found that dyspareunia and vaginal DIE nodules significantly affect sexual activity (P<0.05). Conclusion: The results of this study demonstrated that women with DIE have a sexual function impairment, correlated with the overall well-being decrease. Moreover, the presence of dyspareunia and vaginal endometriotic lesions seems to be involved in sexual dysfunction. © 2013 International Society for Sexual Medicine.