Background Malnutrition contributes to functional and cognitive decline in older adults, which results in decreased quality of life and loss of independence. This study aimed to identify determinants of nutritional risk among community-dwelling adults in KwaZulu-Natal, South Africa. Methods A cross-sectional survey was undertaken in 1008 subjects aged 60 years and over who were randomly selected by systematic sampling. Demographics, socioeconomic data and self-reported history of medical conditions were recorded. The Mini Nutritional Assessment-Short Form (MNA-SF) was used to screen for nutritional risk, and the Centre for Epidemiologic Studies Depression scale was administered to all subjects. Descriptive statistics and the Pearson chi-square and Kruskal-Wallis tests were used for statistical analysis. Logistic regression modelling determined predictors of nutritional risk. Results Of the 984 participants (mean age = 68.8 ± 7.4 years; range 60-103 years) who completed the MNA-SF, 51 % were classified as having a normal nutritional status, 43.4 % at risk for malnutrition and 5.5 % classified as malnourished. Men were more likely to be either at risk for malnutrition or be malnourished than women (p = 0.008), as were subjects with a monthly household income of ≤R1600 per month (~133 USD) (p = 0.003). In logistic regression models, depressed people were 2.803 (p < 0.001) times more likely to be at risk or be malnourished than those not depressed. Conclusion A high prevalence of risk of malnutrition was identified in older South Africans living in an urban area with poor infrastructure. Further investigations are warranted to determine whether the higher prevalence of depressive symptomatology in nutritionally at risk individuals is a determinant or a consequence of malnutrition, in order to develop targeted nutritional interventions in this age group.