The prognostic factors and their intercorrelation in 47 patients with IB endometrial cancer are presented. The data reveal the particular behaviour of the lymphatic involvement: five patients (10.6%) showed metastases to pelvic lymph nodes and six patients (12.8%) had paraaortic node metastases; altogether two women (4.2%) had histological evidence of involvement of pelvic and paraaortic nodes. Both histological grade and depth of myometrial invasion showed a characteristic relationship with the lymphatic spread: the percentage of lymph node metastases seems to bear relation to progression of myometrial penetration (M2-M3) and to histological differentiation (G2-G3).