The objective of the authors was to determine in a prospective study EGFR level of expression in ovarian cancer. For a period of 2 years EGFR expression was studied in 23 patients having malignant ovarian tumors by 125I-labelled human epidermal growth factor and recombinant human epidermal growth factor. EGFR expression was observed in 56.5% of the cases. Insignificant mucinous and clear cell cancers prevailed in the EGFR/+/ group. All patients having wider metastasis were EGFR/+/, as this dependency was statistically significant (p = 0.017). Radioligand binding assays enabled exact quantitative determination of EGFR expression in malignant ovarian tumors. Statistically significant relation existed between the ovarian cancer metastatic potential and EGFR expression level.