Objectives: To examine maternal nutritional status and its relationship to infant weight and body proportions. Design: Retrospective study of births from January±December 1990. Setting: University Hospital of the West Indies, Jamaica. Subjects: Records for 2394 live, singleton births, between 200±305 d gestation. Main outcome measures: Birth weight, crown heel length, head circumference, ponderal index, head circumference:length ratio, placental weight, placental:birth weight ratio. Results: Mothers who were lighter had babies who had lower birth weight, were shorter, had smaller heads and had a higher HC:L ratio. Shorter and thinner women had babies who had lower birth weights, were shorter, had smaller heads and lighter placentas. Thinner women also had babies with a lower placental:birth weight ratio, and their BMI's were not linearly related to ponderal index and HC:L ratio. Women whose ®rst trimester Hb levels were`9.5 g/dl had babies with the lowest birth weight, crown heel length, placental weight and ponderal index. These measurements increased as the Hb levels rose to 12.5 g/dl but then fell at Hb levels b 12.5 g/dl. In the second and third trimester Hb levels were negatively associated with birth weight, crown heel length, head circumference, placenta weight and ponderal index. Conclusions: The data support the hypothesis that poor maternal nutrition is associated with foetal growth restraint. Poor maternal nutrition as indicated by low weight, height, and BMI are associated with smaller, shorter babies with smaller heads. Haemoglobin levels b 12.5 g/dl in pregnancy are associated with lighter, shorter, thinner babies, with smaller heads.