Background. The KwaZulu-Natal (KZN) Province remains one of the provinces mostly affected by under-5 mortality in South Africa, despite the many programmes and policies implemented to prevent under-5 children from dying. Objective. To examine the association between socioeconomic and demographic factors and under-5 mortality in KZN. Methods. The study was cross-sectional and based on a secondary data set from the 2011 national census, conducted by Statistics South Africa. From the 10% sample, 1 474 under-5-year-olds had died in the province during the period of data collection. Statistical analysis was performed in Stata 12.0 and involved univariate, bivariate and multivariate analysis. Results. The results showed that maternal variables such as age, education level and race, as well as annual household income were predictors of under-5 mortality. Male children were also found to have a higher likelihood of dying before the age of 5 years than female children. Conclusion. The study identified several socioeconomic and demographic factors as predictors of under-5 mortality in KZN. The findings suggest the importance of up-scaling and strengthening interventions aimed at reducing under-5 mortality in the province, with specific focus on addressing the needs of young black women, those with limited education and women from poor households.