The serum levels of CA 125 (cutoff limit, 65 U/ml), CA19.9 (cutoff, 40 U/ml), CA 15.3 (cutoff, 32 U/ml), CA72.4 (cutoff, 3.8 U/ml), and TATI (cutoff, 22 ng/ml) were preoperatively measured in 90 patients with epithelial ovarian cancer and in 254 patients with benign ovarian pathology. CA125 had a sensitivity of 75.6%, a specificity of 86.6%, and a diagnostic accuracy of 83.7% for epithelial ovarian cancer; CA19.9 had a sensitivity of 35.6%, a specificity of 81.1%, and a diagnostic accuracy of 69.2%; CA15.3 had a sensitivity of 57.1%, a specificity of 93.9%, and a diagnostic accuracy of 84.6%; CA72.4 had a sensitivity of 70.7%, a specificity of 91.8%, and a diagnostic accuracy of 86.2%; and TATI had a sensitivity of 47.3%, a specificity of 95.3%, and a diagnostic accuracy of 82.9%. CA 125 was the most sensitive marker for nonmucinous tumors, while CA19.9 and CA72.4 were the antigens more frequently expressed by mucinous malignancies. The sensitivities of serum CA 125 (81.1% vs 50.0%; P = 0.01) and TATI (55.2% vs 18.8%; P = 0.02) were higher in patients above 50 years of age than in younger patients while specificities were quite similar in both age groups. The association of serum CA125 and CA19.9 had a significantly higher sensitivity (93.2% vs 81.1%; P = 0.03) and a slightly lowered specificity (78.9% vs 86.0%; P = 0.46) than CA125 assay alone in the differential diagnosis of ovarian masses in patients above 50 years of age.