This study aimed to examine the efficacy of spirulina in treating malnutrition among children in Gaza Strip. The sample of the study consisted of 60 malnourished children aged from 1 - 4 years. Content analysis of Spirulina showed that the proximate components were, crude protein (57.5%), crude fat (7.7%), carbohydrates (23.9%). Mean weight of children who received vitamins and minerals was 8.64 kg initially, increased to 9.39 kg after three months (P= 0.000), and mean weight of children who received spirulina was 7.9 kg initially, increased to 8.58 kg after three months (P= 0.000). There were statistically significant differences in median IQR Ferritin levels, WBC, Hb, HCT, MCV. The study concluded that spirulina was a valuable and effective supplement in treating malnutrition, and could be used in a wide range since it is cheap compared to other pharmaceutical preparations and formulas.