Birth weights and perinatal deaths for the Peninsula Maternal and Neonatal Service were analysed for 1974-1987. There were differences in birth-weight distribution between the ethnic groups, and within the white group, over time, and these influenced the crude perinatal mortality rates. Once birth weight had been adjusted for, there was a downward trend in the data for all groups. The improvement in the perinatal mortality rates was related to better survival in each group. There was no difference in the standardisation rates between the coloured and white infants. Blacks, however, had significantly higher rates when compared with the coloured and white births.