Objective: To build a life table and determine the factors related to the time of treatment of undernourished children at a nutrition rehabilitation centre (CREN), São Paulo, Brazil. Design: Nutritional status was assessed from weight-for-age, height-for-age and BMI-for-age Z-scores, while neuropsychomotor development was classified according to the milestones of childhood development. Life tables, Kaplan-Meier survival curves and Cox multiple regression models were employed in data analysis. Setting: CREN (Centre of Nutritional Recovery and Education), São Paulo, Brazil. Subjects: Undernourished children (n 228) from the southern slums of São Paulo who had received treatment at CREN under a day-hospital regime between the years 1994 and 2009. Results: The Kaplan-Meier curves of survival analysis showed statistically significant differences in the periods of treatment at CREN between children presenting different degrees of neuropsychomotor development (log-rank 5 6?621; P 5 0?037). Estimates based on the multivariate Cox model revealed that children aged $24 months at the time of admission exhibited a lower probability of nutritional rehabilitation (hazard ratio (HR) 5 0?49; P 5 0?046) at the end of the period compared with infants aged up 12 months. Children presenting slow development were better rehabilitated in comparison with those exhibiting adequate evolution (HR 5 4?48; P 5 0?023). No significant effects of sex, degree of undernutrition or birth weight on the probability of nutritional rehabilitation were found. Conclusions: Age and neuropsychomotor developmental status at the time of admission to CREN are critical factors in determining the duration of treatment.Undernutrition is characterised by a complex combination of factors including inadequate or insufficient ingestion of food, deficient intake of essential nutrients, unsatisfactory socio-economic conditions, unhealthy living environment, high frequency of infection and poor health care (1,2) . Evidently, the longer the exposure to such harmful factors the more damaging the consequences to the nutritional status of the individual. The height-for-age indicator reflects linear growth, and is related to long-term changes in nutritional status and overall health (3) . A deficit in this index is associated with cumulative growth retardation indicating chronic undernutrition. The problem of undernutrition is of global concern since, according to the latest FAO estimates, 925 million people ingest insufficient food to meet their minimum energy requirements, of whom 53 million live in Latin America and the Caribbean (4) . In developing countries, approximately 112 million children aged 5 years or less are affected by weight-for-age deficit and 32 % of children in this age group worldwide have been diagnosed with height-for-age deficit (2) . Indeed, height-for-age deficit is currently considered the most important nutritional problem faced by developing countries.In Brazil, 6 % of children aged less than 5 years suffer from height-for-age deficit,...