After our previous studies on the incidence of epidermal growth factor receptors (EGF-R) and its relationships with other tumour characteristics in more than 100 ovarian tumours, in the present study we investigated the prognostic value of EGF-R with respect to progression-free survival in 50 patients with primary ovarian cancer and sufficient follow-up (median 26 months, range 10-33 months). EGF-R was measured by both biochemical and two immunohistochemical methods, using two monoclonal antibodies (MAb), in addition to oestrogen receptors (ER) and progesterone receptors (PgR). EGF-R by ligand binding assay and Scatchard analysis were detectable in 63% of the tumours, by immunohistochemistry with MAb 2E9 in 82% and with MAb EGF-R1 in 78% of the tumours. ER-positivity was found in 58% and PgR-positivity in 38% of the patients. The results of the three measurements of EGF-R showed only weak to moderate associations with Spearman rank correlations (Rs) between 0.13 and 0.46. ER and PgR were only weakly correlated (Rs = 0.20) and they showed no significant association with EGF-R status. There was no clear evidence of the existence of correlations between receptor values and FIGO stage and tumour rest. Univariate Cox regression analyses showed that a higher FIGO stage and larger tumour rest were associated with shorter progression-free survival (P = 0.001), while PgR positivity was associated with a longer progression-free survival (P = 0.02). The level of EGF-R (irrespective of the method of determination used) showed a positive correlation with the risk of progression, but this correlation was not statistically significant.