Résumé : Objective To assess under real community settings the effectiveness of the WHO strategy of home fortification of foods (HFF) with multiple-micronutrient powders on Hb change, anaemia and weight in children.Design A pragmatic cluster-randomized controlled trial.Setting Forty villages in the Nioro Circle in Mali and 722 children aged 6-23 months were randomized to the intervention or control group. The intervention consisted of a daily dose of multiple-micronutrient powder for 3 months; in the control group, no supplement was given. In both groups, mothers received group education on child complementary feeding. Changes in weight, Hb concentration and anaemia were assessed as primary outcomes at baseline and 3 months. The HFF effect was determined using regression analyses and quantile regression with standard errors taking account of the cluster design.Subjects Children aged 6-23 months.Results Overall prevalence of anaemia in the sample was high: 90 %. HFF provided a modest but statistically significant Hb change v. no intervention (0·50 v. 0·09 g/dl, P=0·023). Prevalence of anaemia changed little: 91·3-85·8 % (P=0·04) in the intervention group v. 88·1-87·5 % % (P=0·86) in the control group. Proportion of severe anaemia was reduced by 84 % (from 9·8 to 1·6 %) in the intervention group, but increased in the control group (from 8·5 to 10·8 %). No effect was observed on weight.Conclusions The WHO HFF strategy to fight anaemia showed a modest change on Hb concentration and significantly reduced the rate of severe anaemia.