Between April 1968 and May 1973 the department of International Health of The Johns Hopkins University carried out investigations into the interactions of malnutrition and infection and their effects on preschool child growth, morbidity and mortality in 10 villages of Punjab, North India. Base line surveys before the introduction of services revealed a high prevalence of malnutrition and undernutrition and infectious disease morbidity, as well as lack of accessibility, underutilization, and poor population coverage of governmental health services. Study villages were selected in separate clusters and allocated to a control group and three service groups in which nutrition care and medical care were provided singly and in combination by auxiliary health workers resident in each village. Outcome effects were measured through means of longitudinal and cross-sectional surveys. Service inputs and service costs were similarly monitored. Results showed significant improvement of growth (weight and height) and hemoglobin levels of children. Perinatal mortality was reduced by nutrition supplementation to pregnant women. Medical care significantly reduced postneonatal and 1 to 3 mortality, and decreased illness duration of all six conditions examined in this paper. The auxiliary health worker capably managed more than 90% of health needs on her own and referred the rest safely to the physician. Analysis of cost per child death averted showed that cost-effectiveness declined with increasing age of the child. Prenatal nutrition care to pregnant women was most cost-effective in preventing perinatal deaths followed by medical care for infants, and then medical care for the 1 to 3 year age group. The relevance of the field research to national or international endeavors to solve present health problems of developing nations and the timeliness of projects such as the Narangwal Nutrition Study is also evaluated.