To determine whether prevalence and severity of pain symptoms are related to endometriosis stage and site, with particular reference to deep infiltrating vaginal lesions. Systematic assessment of chronic pelvic pain symptoms. University hospital endometriosis center. A total of 244 consecutive symptomatic patients with endometriosis diagnosed at laparoscopy or laparotomy. Assessment of dysmenorrhea and nonmenstrual pain by means of a 10-point linear analog scale, a 7-point multidimensional rating scale, and a 3-point verbal scale; evaluation of deep dyspareunia with the first and third systems only. Prevalence and severity of pain symptoms in relation to endometriosis stage and site of lesions. Correlation between revised American Fertility Society score and symptoms severity, as well as between two pain scales to assess dysmenorrhea and nonmenstrual pain. Eighty-eight women had stage I and II disease and 156 had stage III and IV disease. Only ovarian endometriosis was present in 108 patients, only peritoneal implants were present in 37, combined ovarian and peritoneal lesions were present in 57, and histologically confirmed vaginal endometriosis was present in 42. The frequency and severity of deep dyspareunia and the frequency of dysmenorrhea were less in patients with only ovarian endometriosis than in those with lesions at other sites. Patients with vaginal endometriosis had a significantly increased risk of deep dyspareunia compared with those whose lesions were at other sites (odds ratio, 2.55; 95% confidence interval, 1.21 to 5.39). Stage per se, independent of lesion site, was not correlated with frequency and severity of dysmenorrhea and nonmenstrual pain. The severity of deep dyspareunia was related inversely to the endometriosis score (Spearman correlation coefficients for linear analog and verbal rating scales, respectively, -0.22 and -0.20). Kendall test by ranks revealed a correlation between linear analog and multidimensional pain scales in the rating of both dysmenorrhea and nonmenstrual pain (respectively, tau-b, 0.59 and tau-b, 0.68). Endometriosis stage in the current classification was not related consistently to pain symptoms. The presence of vaginal lesions was associated frequently with severe deep dyspareunia. Dysmenorrhea and nonmenstrual pelvic pain were assessed with equal accuracy by a linear analog and a multidimensional scale.