Abstract: Iron deficiency anemia is one of the most common micronutrient deficient conditions around the globe with various consequences, including the weakened immune system. Quercetin is widely distributed bioflavonoid; it has been debated for its dual roles in iron regulation. Quercetin-iron interaction in the body is a complex mechanism which has not been completely understood. The present study aimed to investigate the effect of quercetin on iron supplementation in iron deficiency anemia and on iNOS expression in splenic macrophages. The rat model of iron deficiency anemia was induced by feeding low iron diet to weanling rats for 20 days. The animals were then administered with ferrous sulfate, quercetin, and their combination for 30 days. Blood parameters, histopathological analysis, iron storage, CD68, iNOS and SLC40 expression in rat spleen were investigated. Our results showed that quercetin regulated iron absorption, despite SLC40 down-expression, indicating possible alternate route of iron transport, and that quercetin modulated iNOS production in splenic macrophages.