Objective: To describe fetal growth centiles in relation to maternal malaria and HIV status, using cross sectional measurements at birth. Design: A cross sectional study of pregnant women and their babies. Data on maternal socioeconomic status and current pregnancy, including HIV status and newborn anthropometry, were collected. Malaria parasitaemia was assessed in maternal peripheral and placental blood, fetal haemoglobin was measured in cord blood, and maternal HIV status was determined. Setting: Two district hospitals in rural southern Malawi, between March 1993 and July 1994. Outcome variables: Newborn weight, length, Rohrer’s ponderal index. Results: Maternal HIV (adjusted odds ratio (AOR) 1.76 (95% confidence interval 1.04 to 2.98)) and first pregnancy (AOR 1.83 (1.10 to 3.05)) were independently associated with low weight for age. Placental or peripheral parasifaemia at delivery (AOR 1.73 (1.02 to 2.88)) and primigravidae (AOR 2.13 (1.27 to 3.59)) were independently associated with low length for age. Maternal malaria at delivery and primiparity were associated with reduced newborn weight and length but not with disproportionate growth. Maternal HIV infection was associated only with reduced birth weight. The malaria and parity effect occurred throughout gestational weeks 30-40, but the HIV effect primarily after 38 weeks gestation. Conclusion: Fetal growth retardation in weight and length commonly occurs in this highly malarious area and is present from 30 weeks gestation. A maternal HIV effect on fetal weight occurred after 38 weeks gestation