A retrospective analysis of 36 patients with metastatic nodes out of 209 consecutively managed patients with a clinically stage I endometrial cancer was carried out. Of the 1023 lymph nodes removed, 154 nodes were found to be metastatic. The mean number of the involved nodes was 4.27 (range: 1-29). Of the 154 positive nodes, 3 had nodal diameters < or = 3 mm (1.9%), 84 had diameters of 4-10 mm (54.6%), 60 had diameters of 11-20 mm (39.0%) and 7 had diameters more than 20 mm (4.5%). With increasing lymph node size, the frequency of tumoral involvement varies from 1.0% in nodes < or = 3 mm to 63.6% in nodes bigger than 20 mm. In terms of patients, nine of them were found to have a single metastatic node ranging from 6 mm to 10 mm in diameter. In the remaining 27 patients with multiple metastatic nodes, the biggest nodes encountered were 6-10 mm in 4 (14.8%), 11-20 mm in 17 (62.9%) and more than 20 mm in 6 (22.2%) patients. Since mere sampling of the lymphatic tissue directed particularly to the enlarged nodes may not show the true incidence of positive nodes, a complete lymphadenectomy is advocated in order to obviate an understaging problem.