From 1979 to 1984, 127 patients operated on for ovarian cancer underwent pelvic, para-aortic, or pelvic and para-aortic lymph node sampling. Forty-seven patients proved to be stage I(14 IA and 33 IC), 14 were stage II(3 IIA, 8 IIB, and 3 IIC), 58 were stage III (7 IIIA, 13 IIIB, and 38 IIIC), and 8 were stage IV. Positive lymph nodes were found in 4.2% of patients at stage I, 35.7% at stage II, 41.3% at stage III, and 87.5% at stage IV. With regard to grading, positive lymph nodes were found in 4.4% of G1, in 21.6% of G2, and in 49.1% of G3. A significant increase in survival (P = 0.04) was found for patients classified as stage IIIC only according to lymph node involvement compared to patients in peritoneal stage IIIC with positive lymph nodes (3-year survival: 46% vs 12%). A small increase in survival was observed for N- patients compared to N+ patients, at both stage III and IV, even with same residual tumor size, but the difference is not statistically significant. All other things being equal, because the prevalence of lymph node positivity depends closely on the number of lymph nodes removed and examined (OR = 3.9 for >10 lymph nodes removed compared to 1-5 lymph nodes removed), lymph node sampling does not seem to be a reliable method for evaluating the retroperitoneal status. With regard to the therapeutic role of systematic lymphadenectomy, few data in literature are available and, most important, are not derived from experimental studies. Probably, only randomized studies with a large number of patients will provide useful answers.