To establish a new predictor of the outcome of treatment for human cervical carcinoma, we investigated the relationship between the expression of the Bax and Bcl-2 proteins and the response to radiotherapy after administration of 10.8 Gy. A total of 44 patients with uterine cervical carcinoma were treated with definitive radiotherapy. On univariate analysis, Bax and Bcl-2 protein expression prior to radiotherapy did not correlate with survival. Increased Bax expression after 10.8 Gy correlated with good survival (p = 0.003). In contrast, increased Bcl-2 expression after 10.8 Gy correlated with poor survival (p < 0.0001). On multivariate analysis, Bcl-2 expression after 10.8 Gy of radiation was the most important predictor of treatment outcome. The levels of Bax and Bcl-2 expression after 10.8 Gy of radiotherapy are useful prognostic markers in patients with human cervical carcinoma.