This paper is concerned with the relationship between child mortality and the use of health care. We develop a simultaneous model of fetal and postnatal mortality risks and input demand equations for prenatal medical care and institutional delivery. This model is applied to retrospective data from Peninsular Malaysia covering 1950-1988. The results show that prenatal medical care and institutional delivery have strong beneficial effects on child survival probabilities, and that these effects are substantially underestimated when adverse self-selection among users of health care is ignored. The effectiveness of prenatal health care in Malaysia improved until 1980, and then deteriorated. We find that the risk of infant and child mortality is not independent of fetal survival, but show that ignoring selective fetal survival introduces only mild biases in infant and child mortality estimation. Higher infant and child mortality rates among young mothers are partly explained by their lower likelihood of purchasing health care.