Malnutrition remains one of the most common causes of morbidity and mortality among children throughout the world.The study aimed at evaluating the effect of Moringa oleifera leaf powder in improving the nutritional status of children 6 to24 months of age in Arusha Municipality. A total of 140 children were enrolled and randomly allocated to two treatments where by 64 children received moringa leaf powder porridge and 76 children received maize porridge and a randomized control design was used. Anthropometry and morbidity data were collected during monthly household visits for three consecutive months. LSD was used for the comparison of means; unpaired t-test was used for the comparison of two groups. Mean weight-for-age Z-scores (WAZ) for infants in treatment and control group increased from -4.1 and -3.6 at baseline to -2.2 and -3.3 at the end. Likewise, the mean weight-for-length z-scores (WLZ) for infants in treatment and control group increased from -3.4 and -3.4 at baseline to -1.1 and 3.2 at the end respectively. Mean length-for-age z-scores (LAZ) for infants in treatment group increased from -3.2 at baseline to -2.6 end of intervention in contrast to infants in control group which declined from -2.0 at baseline to -2.4 at the end. At baseline 13% and 21% of children in the treatment group had diarrhoea and malaria, respectively but the prevalence decreased significantly to 1.4% and 0.7%, respectively at the end of the intervention. Mean haemoglobin concentration of the children increased from 7.4 to 11.5 for the treatment group while in the control group it increased from 7.1 to 7.3. In this regard, it may be concluded that M.oleifera leaf powder had significant positive effect on child nutritional status and morbidity. The use of M.oleifera leaf powder is recommended for addressing the problem of undernutrition in Tanzania.Mr and Mrs Andrew Shayo