Cell kinetic parameters of labeling index (LI), duration of S-phase (Ts), and potential doubling time (Tpot) were analyzed following infusion of bromodeoxyuridine (BUdR) in 33 patients with various epithelial cancers. Twelve uterine cervical cancers, 9 rectal cancers, 7 head and neck caneers, and 5 bladder cancers were included. Biopsies were taken about 4-6 h after 200 mg/m(2) BUdR infusion and the samples were anaiyzed with bivariate DNA /BUdR flow cytometry. The distribution of cell kinetic parameters for the 33 epithelial cancers showed a large range of values for each parameter. The median LI, Ts, and Tpot were 4.5%, 10.8 h, and 242.3 h, respectively. Eight among 33 patients (24.2%) showed aneuploidy. In aneuploid tumors the distribution of LI, Ts, and Tpot was in relatively small range. Aneupliod tumors appeared to show higher LI and shorter Tpot than those in diploid tumors. In diploid tumors, the poesibility of normal cell contamination could not be ruled out. The results of this study would be a basis for future trial to predict which ones would show tumor clonogen repopulation during radiotherapy so that benefit from altered fractionated radiotherapy.