DNA flow cytometry (FCM) investigation of tumor specimens before and after 30 Gy 137Cs radiation treatment was performed in 33 cases of epidermoid uterine cervix carcinoma. Distinct differences in the type of FCM response to radiation were seen when the results of DNA index (DI) in diploid and aneuploid tumors and proliferation index (PI) values in diploid tumors from pretreatment and 30 Gy irradiated specimens were compared. We observed partial or total reduction of PI in 12 of 17 diploid and near diploid tumors, and total reduction of the aneuploid population in 14 of 16 aneuploid tumors. No significant correlation was found between the type of FCM response and clinical stage of the disease or the histological degree of differentiation.