Background: Assessment of blood and blood components requisition and utilization is essential for better planning and improvement of transfusion services to meet requests and demands. The main aim of this study is to assess the collection and utilization of blood and blood components in Zanzibar National Blood Transfusion Services (ZNBTS). Method: It is a retrospective study in which data relating to the collection and usage of blood and its components from January 2021 to December 2021 at ZNBTS was collected and analyzed. Results: A total of 16,388 units of blood were collected from January to December 2021. 21,265 units of blood components were generated from 8,585(55.0%) units of Whole Blood (WB), while the remaining 7,030 (45.0%) units were issued as WB. In Unguja, there was a significant increase in the use of Packed Red Blood Cells (PRBC) 10,177 (61.3%), followed by WB 3,759 (22.6%), Fresh Frozen Plasma (FFP) 1, 562 (9.4%) and Platelets (PLT) 10 (0.06%) respectively. In Pemba, the use of WB was high (n = 1,526; 69.8%), followed by PRBC 878 (3.6%) and FFP 68(0.4%). The monthly mean blood request was 2,975 units (WB 460 and Blood components 1,028). Blood collection was above ZNBTS annual target of 16,000 units but blood and blood components request was met only by 50%. Conclusion: There is a gradual shift in clinical practice from the traditional use of WB to the use of PRBC and other blood components. For the appropriate use of blood and blood components, Transfusion Medicine training among Medical Students and junior clinicians is strongly recommended.