The purpose of this study was to investigate the correlation between the spontaneous apoptotic index (SAI) determined from pretreatment biopsy specimens with the various clinical outcomes of patients with FIGO stage IIB squamous cell carcinoma of the uterine cervix in a retrospective analysis. Forty-eight patients treated with curative radiotherapy between 1989 and 1993 were evaluated. Pretreatment biopsy specimens of those patients were scored for apoptosis, mitosis, and proliferating cell nuclear antigen (PCNA) immunohistochemical staining. The range of the SAI was 0.2-4.7% (median 1.1%). Patients whose tumours had a SAI above the median had better local control (p = 0.0062) and overall survival (p = 0.0053) than those with a lower SAI. Furthermore, the SAI was marginally significant on local control by a multivariate Cox regression analysis (p = 0.0571). There was no correlation between the SAI and proliferation (mitosis and PCNA).