To provide evidence regarding the significance of painful symptoms among women suffering from infertility. An observational retrospective cross-sectional study SETTINGS: University hospital-based research center PATIENTS: Infertile patients aged between 18-42 years surgically explored for benign gynecological conditions between 01-2004 and 12-2020. For each patient, a standardized questionnaire was completed during a face-to-face interview conducted by the surgeon in the month preceding the surgery. Preoperative assessment the pain symptoms was recorded. Pain intensity was assessed with a 10cm visual analog scale (VAS). The pain was considered to be severe when the VAS score was ≥ 7. Surgery was performed in 839 infertile women. 451 women had severe pelvic pain. Infertile patients with severe pain significantly more often had endometriosis (67.4% versus 30.7% respectively; p<0.001) than infertile women without severe pelvic pain, and especially deep infiltrating lesions (43.2% versus 8.5% respectively; p<0.001). Moreover, these women more often had intestinal endometriosis lesions (28.4% versus 1.8%; p<0.001). After multivariable regression analysis, the presence of endometriosis, irrespective of the phenotype (superficial lesions (OR1.84[1.19-2.86] and/or ovarian endometrioma OR 2.79[1.70-4.59] and/or deep infiltrating endometriosis OR 4.49[2.69-7.51]), and the presence of at least one intestine endometriosis lesion (OR6.49[2.69-7.51] were significantly associated with severe pelvic pain. Severe pelvic pain is significantly associated with endometriosis and especially deep infiltrating lesions in a population of infertile women. These results demonstrate the importance of thorough questioning regarding pelvic pain symptoms during the initial management of infertile patients.