The mean annual number of cancer cases reported by hospitals in four districts of Transkei during the period 1981 - 1984 was 413. The age-standardised incidence rates (African standard) for cancer (all reported cases) were 51.0 and 52.0/100,000 per annum for males and females respectively. Histopathological examination of 48% of the reported tumours revealed that 71.3% were squamous carcinomas, 16.4% adenocarcinomas and the remainder non-epithelial neoplasms. The most frequently reported cancer was oesophageal cancer (OC), which represented 45.8% of all reported cancer cases. The mean age-standardised incidence rates for OC were 28.4 and 17.8/100,000 for males and females respectively. The male/female ratio was 1.6:1. The incidence of OC in both sexes was higher in the two south-western districts (Butterworth and Kentani) than in the two north-eastern districts (Bizana and Lusikisiki). The highest mean rates (45.0 and 29.3/100,000 for males and females respectively) occurred in Kentani and the lowest rates (19.5 and 15.0/100,000) in Bizana. Comparison of OC rates in the four districts during 1981 - 1984 with previously reported rates for the periods 1955 - 1959 and 1965 - 1969 revealed a consistently high rate in Kentani, a high but decreasing rate in Butterworth, and progressively increasing rates in Bizana and Lusikisiki. The second most common cancer among males was liver cancer, with a mean incidence rate of 4.8/100,000. The highest incidence of liver cancer (7.7/100,000) also occurred in Kentani. The male/female ratio was 2.7:1. The second most common cancer among females was cervical cancer (20.1/100,000), followed by breast cancer (4.0/100,000). Incidences of all other tumours were below 3/100,000.