Thousands of children younger than 5 years of age still die all over the world as a result of preventable diseases. Community intervention measures emphasizing primary health and nutritional care have been identified as one of the solutions to this problem. This article describes a population-based cross-sectional study of the Pastoral da Criança, a Roman Catholic health support group in Brazil. The study assesses whether mothers and children assisted by the Pastoral present better health indicators and have a better knowledge of basic child survival actions than non-assisted mothers and children. The study was carried out in 1996 in an urban area of the municipality of Criciúma, in the state of Santa Catarina, in southern Brazil. The sample was composed of 2,208 children under 3 years of age. The adjusted analysis taking into consideration possible confounding factors showed that the presence of the Pastoral was significantly associated with maternal knowledge of appropriate feeding measures during diarrheal episodes, optimal duration of exclusive breast-feeding, implications of feeding powdered milk to infants, correct interpretation of the infant growth curve, and knowledge of the proper vaccination schedule for infants. Participation in the Pastoral was positively associated with longer total breast-feeding duration, later introduction of bottle-feeding, higher frequency of growth monitoring visits in the quarter before the study, and availability in the home of measuring spoons for oral rehydration. No significant association was found between participation in the Pastoral and duration of predominant or exclusive breast-feeding, or correct diarrhea management. The results showed Pastoral actions have a positive effect and also revealed areas in which greater investments are needed. It is recommended that the Pastoral, as well as other similar institutions, give priority to educating mothers on child care and to recruiting mothers early in pregnancy, when the impact of these actions is potentially greater.