AIM: To test which immunohistochemically detected tumour parameters are predictive of outcome in endometrial carcinoma. METHODS: A retrospective study of 300 patients diagnosed with endometrial carcinoma between 1980 and 1985, ensuring a follow up of at least 10 years. Paraffin wax embedded tissues from 236 patients with endometrial carcinoma were evaluated in terms of histological tumour type and grade, stage of disease, and certain immunohistochemical biological parameters. These parameters included the expression of oestrogen and progesterone receptors, the expression of p53 protein, the expression of the c-erbB-2 oncoprotein, and the expression of protease cathepsin D, together with the rate of cell proliferation. RESULTS: Using univariate analysis, the following parameters correlated significantly with adjusted survival: histological type (p = 0.025), grade (p = 0.00003), FIGO stage (p < 0.00001), proliferation rate (p = 0.00002), oestrogen receptor expression (p = 0.007), progesterone receptor expression (p = 0.0092), and p53 expression (p = 0.00028). These parameters also correlated significantly with both disease free and overall survival. There was a weak correlation of cathepsin D expression with survival, but no correlation of c-erb B-2 expression with survival. Using multivariate analysis, only FIGO stage (p = 0.0021), histological grade (p = 0.005), and proliferation rate (p = 0.0007) remained statistically significant prognosticators of adjusted survival as well as of disease free and overall survival. CONCLUSIONS: In addition to conventional histological parameters, the immunohistochemical determination of proliferative activity could contribute to the identification of a high risk subgroup of endometrial carcinomas. The other parameters tested were not of significant additional predictive value.