Malnutrition has a deleterious effect on the results of therapy for malignant diseases in childhood. The impact of radiotherapy on growth is well known but the impact of cytotoxic drugs on nutritional status is more controversial. The purpose of this study was to determine the nutritional status of a cohort of children treated for acute lymphoblastic leukaemia (ALL) in Cuba. The study involved 49 children admitted to a single center and treated with a Berlin-Frankfurt-Munster-based protocol. Nutritional assessment included measurements of height, weight, body mass index and skin-fold thickness, made at diagnosis, after the intensive phase of treatment and at the end of therapy. Z-scores were used for height and comparison of percentiles for the rest of the variables. All the patients were above the third percentile in all the measurements. There were no statistically significant differences between the results at diagnosis, after intensive therapy and at the end of treatment. Although the sample was small, there was no demonstrable effect of chemotherapy on nutritional status in this Cuban paediatric population, in contrast to that reported in children with ALL in other developing countries.