In a prospective study including 447 patients with endometrial adenocarcinoma stages I and II, clinical and flow cytometric variables were studied in univariate and multivariate analyses. During the follow-up period of 3 to 65 months, 41 patients died of their disease and 26 patients died of intercurrent disease. Based on the results of multivariate analyses, five different prognostic indices were constructed. Using these indices, individual index values were calculated for each patient. The index values were correlated with survival and were used to identify a small high-risk group (10% of the patients) and a large low-risk group (90% of the patients). Indices 1 and 2 were constructed for pre-treatment situations. Index 1 included age and histopathologic grade and identified a small high-risk group and a large low-risk group with a 3-year survival of 62% and 91% respectively. Index 2 also comprised S-phase fraction and distinguished a high-risk group with a 3-year survival of 54% from a low-risk group with a 3-year survival of 93%. Indices 3 and 4 were constructed for patients after surgery, when the degree of residual myometrial tumor invasion was known. Index 3 included age, histopathologic grade and residual myometrial invasion rendering a 3-year survival of 44% and 93% for the high- and low-risk groups respectively. Index 4 also comprised S-phase fraction and identified a high-risk group and a low-risk group with 3-year survival figures of 59% and 96%, respectively. Index 5 included age and histopathologic grade and was constructed for post-treatment situations in unoperated patients. The index separated a high-risk group from a low-risk group with a 3-year survival of 56% and 88%, respectively. In summary, the results from our study show that the prognostic indices made it possible to identify high and low-risk groups in different clinical situations which may prove useful in selecting candidates for future trials with adjuvant or reduced treatment.