The DNA content of 59 adenocarcinomas of the stomach in patients who had undergone subtotal or total gastrectomy more than 5 years before was measured. The DNA measurements were done by flow cytometry performed on Propidium Iodide--stained cells disaggregated from paraffin-embedded tissues. Fifty-nine evaluable good quality histograms of DNA ploidy patterns were obtained. The Proliferative Index (PI) was determined in 35 cases. The remaining 24 cases didn't show a reliable reading histograms. Of the 59 tumors, 33 (56%) were diploid and 26 (44%) were aneuploid; 19 showed a high PI (> or = 3.8%) and 16 a lower one. A statistically significant difference was found between the two groups (diploid/aneuploid and low/high PI) compared to the prognostic values known as T, N and Stage. 65% of the T3-T4 cancers, 54% of the N1-N2 lesions and 58% of the stage III and IV were found to be aneuploid. 73.7% of the 19 tumors presenting high PI, showed an aneuploid pattern. A high PI was found in 71.4% of the T3-T4 tumors. 77.4% of patients of the diploid group (any stage) survived at 5 years against 36% of those presenting aneuploid patterns. Patients with PI > or = 3.8% showed a 42.1% 5-year survival rate. A 94.4% 5-year survival rate of diploid and early stage cancers was documented against a 33.5% of aneuploid and advanced stage cancers.