Abstract: The South African Demographic Health Survey data set (SADHS) of 2003 contains massive individual-level information on South African children under the age of five years selected from a random sample of 7756 households. The data set contains data on socio-economic, demographic, health-related and sanitary variables gathered by using multistage cluster sampling. The objective of the study was to identify key predictors of mortality amongst children under the age of five years. Logistic regression analysis and Cox regression were used for data analysis. Under-five mortality was significantly influenced by three predictor variables (breastfeeding, marital status, and ownership of a flush toilet). The hazard ratio of the variable 'breastfeeding' was 3.09 with P = 0.000 and 95% confidence interval (CI) of (1.899, 5.033). The hazard ratio of the variable 'toilet' was 2.35 with P = 0.016 and 95% confidence interval of (1.172, 4.707). The hazard ratio of the variable 'marital status' was 1.74 with P = 0.035 and 95% confidence interval of (1.041, 2.912). Adjustment was factored in for the mother's level of education and wealth index.