Dissertation (MSc Pediatric Nursing)Background: Caregivers‟ competence in nutrition is significant in preventing iron deficiency anemia to children. Unfortunately, most caregivers lack competence on nutrition and its role in prevention anemia to under-five children. The aim of this study was determine the level of anemia and determinants of nutritional competence on the prevention of anemia among caregivers of under-five children in Zanzibar. Method: A cross-sectional study design using quantitative approach was undertaken to 297 participants recruited by multi-stage sampling technique. The tools for data collection involved a structured questionnaire and automated hemoglobin machine serial no 301. Both descriptive and inferential analysis was conducted by using SPSS version 20. Results: The overall prevalence of anemia among under-five children was 69.1%. The prevalence for Unguja was 77.9%, and 64.2% for Pemba. About 36.7% of caregivers had adequate knowledge, 43.4% had positive attitude, and 49.8% had good nutritional practices. Residence was the predictor of caregivers‟ knowledge (AOR= 2.153, P = 0.004), attitude (AOR =0.392, p =0.000) and practice (AOR=1.810, P=0.031). Caregivers‟ income was the significant predictor for knowledge (AOR=0.544, P=0.022), and nutritional practice (AOR=2.164, P=0.003).Unfortunately, in this study, caregivers knowledge, attitude and practice were not showed association with occurrence of anemia to the under-fives children regardless some literatures showed to have association. Conclusion: Knowledge, attitude and practice of the caregivers toward prevention of anemia is still low in Zanzibar. Therefore, multidisciplinary collaboration is needed to address this problem so that to overcome anemia problems among under-five children.