Objective: The aim of the study was to examine the relationships between nutritional status and diarrhoea and respiratory infections. Design: Prospective cohort study within the framework of a randomized double-blind placebo-controlled intervention trial. Setting: In rural communities in the Khartoum and Gezira regions, in Northern Sudan. Subjects: 28, 753 Sudanese pre-school children between 6 months and 6 y old. Methods: Relative risks of subsequent diarrhoea and respiratory infections in relation to nutritional status measured by anthropometry (Z-scores of height-for-age (H/A), weight-for-height (W/H), and weight-for-age (W/A), which reflect stunting, wasting and underweight, respectively) were estimated using odds ratios from logistic regression adjusting for various covariates. Results: H/A, W/H and W/A were significantly and inversely associated with subsequent diarrhoea and febrile diarrhoea (P for trend