CA-125, a high-molecular-weight glycoprotein antigen, has been identified as a possible marker for endometriosis, with discrepant results. CA-72, another glycoprotein antigen, is expressed by a variety of adenocarcinomas, including endometrial carcinoma. This controlled, prospective study evaluated serum CA-125 and CA-72 levels in 35 consecutive patients with endometriosis of varying stages and in patients without endometriosis. Serum CA-125 and CA-72 were measured with immunoradiologic methods prior to diagnostic laparoscopy for infertility evaluation. Endometriosis, scored by American Fertility Society guidelines, was identified in 19 patients, and 16 patients had normal pelvic findings. CA-125 and CA-72 levels were not different between patients with no pelvic disease (controls) and women with stage I-IV endometriosis. The positive predictive value of CA-125 was 0%; the negative predictive value was 47%. The positive predictive value of CA-72 was 5%; the negative predictive value was 53%. CA-72 and CA-125 are not helpful in the routine workup of the infertile woman to determine the likelihood that she has pelvic endometriosis.