Anthropometric data are presented on 412 rural Gambian infants measured longitudinally from birth to 18 months of age. Maternal parity was shown to exert a marked influence on growth. Firstborn babies had significantly depressed birthweights (parity 1: 2.79 +/- 0.06 kg, n = 62; parities 2-9: 3.05 +/- 0.09 kg, n = 309; P less than 0.001) but catch-up growth was complete by 3 months. In contrast, children born to mothers of very high parity (10 and above) had average birthweights (2.90 +/- 0.07 kg, n = 41) but early growth was poor. At 3 months their weights, mid-upper arm circumferences and triceps skinfolds were significantly below those of other infants (eg, weight-for-age (% NCHS): parities 10+: 90.3 +/- 2.3 per cent; parities 2-9: 97.4 +/- 2.7 per cent; P less than 0.01). Supine length and head circumference were not affected. After 3-6 months all children experienced severe growth retardation reflected in poor weight, length and head circumference gains. No catch-up growth occurred in the high parity group. Consequently, anthropometric differentials set up by 3 months were maintained throughout infancy (eg, weight-for-age at 12 months: parities 10+: 76.4 +/- 1.9 per cent; parities 2-9: 81.5 +/- 2.6 per cent; P less than 0.01). The relationship between these infant growth patterns and maternal lactational performance is discussed.