OBJECTIVE: To compare development of 17 children aged 12 months with iron deficiency anaemia (IDA) and 18 controls without IDA after a 3-months follow-up period and iron therapy in the IDA group. SUBJECTS AND METHODS: Development of all children was evaluated using the Griffith's Scale. Data was collected on parent's social class and education, breast-feeding, number of siblings and clinical nutritional status. RESULTS: At 12 months children with IDA had significantly lower development scores--mean (sd)--than those without IDA: 112(5) vs. 121(7). At 15 months, after iron therapy, there were no significant differences between cases and controls. Non-IDA children showed significantly lower development scores at 15 months when compared with 12 months (121 vs 115). CONCLUSIONS: The study shows that iron therapy can revert some of the adverse effects in the development of children with IDA and therefore both IDA prevention and treatment can be justified.(undefined