One of the health problems in Indonesia is the high prevalence of stunting in infants. Determinants and specifically the relative contribution of prenatal and postnatal factors to growth and nutritional status of Indonesian infants were investigated. Newborn infants, from women recruited at approximately 18 wk of pregnancy from 9 rural villages in West Java, Indonesia, were followed until 12-15 mo of age. Weight, length, morbidity, breast-feeding and food intake were assessed monthly. Determinants of length and weight increase and nutritional status reflected by Z-scores were evaluated using multiple linear regression. Neonatal weight (3.2 +/- 0.5 kg) and length (49.7 +/- 2.2 cm) were reasonable. However, growth started to falter at 6-7 mo of age, resulting in prevalences of 24% stunting and 32% underweight at 12 mo of age. The multiple regression models explained 19-41% of the variation in growth and nutritional status of infants. Neonatal weight (beta = 0.285) and length (beta = 0.492) were the strongest positive predictors of weight-for-age and height-for-age Z-scores, respectively. Fever was negatively associated with weight increase (beta = -0.144) and weight-for-age (beta = -0.142) and weight-for-height Z-scores (beta = -0.255) but not with length increase or height-for-age Z-scores. Intake of complementary foods was positively associated with increases in weight (beta = 0.190) and length (beta = 0.179) and nutritional status of infants (beta = 0.136-0.194). In conclusion, in this rural population in West Java, neonatal weight and especially length, reflecting the prenatal environment, are the most important predictors of infant nutritional status.