This work uses data from the Survey of Infant and Child Mortality (EMIJ) in Yaounde, Cameroon, to examine the causes and determinants of mortality among children under age 2 in sub-Saharan Africa. The EMIJ provided detailed information on demographic and socioeconomic background, morbidity, and mortality for 9774 infants born in 1978 to mothers residing in Yaounde, with follow-up visits at 1, 4, 8, 12, 16, 20, and 24 months. The work first examined theoretical frameworks for analysis of the causes and determinants of pediatric mortality. The strategy of seeking relationships between the biological processes of disease and death and social factors in the family and environment is described and placed in the context of existing research. Available sources of data for study of pediatric mortality in developing countries are then assessed, and the advantages of the Yaounde EMIJ are detailed. The effects of five large groups of factors on mortality by cause are examined: socioeconomic factors, standard of living, biological and behavioral factors, sex and birth weight, and public health. The classic life table method was used with tests of significance for observed mortality differences from different causes. Multivariate and multistate regression models were used to study survival. Risks of death from diarrhea, malaria, measles, and other causes were considered. The results demonstrated that mortality varies significantly as a function of socioeconomic factors, especially maternal education, employment, and marital status, and household income, standard of living, birth spacing, breast feeding, birth weight, and vaccination. These factors were associated with significant differences in total mortality of infants aged 0-24 months and also in causes of death.