A retrospective study was mounted into the frequency of breast cancer in blacks, whites and Asians attending Dudley Road Hospital in the years 1970-1981 inclusive. This figure was compared with the ethnic distribution of the surrounding population and of admissions for all causes. Breast cancer was uncommon in both ethnic minorities compared with whites, but was commoner in blacks than in Asians. These trends are similar to the World Health Organization figures for Britain, Jamaica and India. Differences in parity and breast feeding do not explain the variability of breast cancer in this study.