Objective: To analyse the trends and factors associated with anaemia in 6-to 59-month-old children in Northeast Brazil. Design: Cross-sectional study assessed information from the second and third Pernambuco State Health and Nutrition Surveys carried out in 1997 and 2006. A multiple regression analysis was performed from a conceptual model addressing biological and socio-economic factors, housing and sanitation conditions, maternal factors, health care and nutrition, consumption, morbidity and nutritional status. Poisson's regression with robust variance was used. Setting: Pernambuco, Brazil. Subjects: A total of 777 and 993 children, respectively, in the second and third Pernambuco State Health and Nutrition Surveys. Results: The prevalence of anaemia (Hb , 11 g/dl) decreased by 19?3 % (40?9 % down to 33?0 %) between surveys. Maternal education level (less than 8 years in school), households ranked in the lowest environmental index tertile and children between 6 and 23 months of age were the variables common to the final models in the surveys of 1997 and 2006. Elements like living in rural areas, household income less than two minimum official wages and low birth weight were still present in the final model of the 1997 survey. Households ranked in the lowest economic index tertile were associated with anaemia in the model of the 2006 survey. Conclusions: The study results are quite encouraging from the perspective of reducing the prevalence of anaemia. Maternal education level, environmental conditions and child age were determinant factors in both surveys, and economic factors were determinant in 2006.