A research report submitted to Mzumbe University as it is a partial fulfillment requirement of the award of the degree of Masters of Science in Procurement and Supply Chain Management (MSc. PSCM) of Mzumbe University,Inventory administration is considered most important aspect to an association's success in the serious and dynamic market; this involves a decrease in the cost of holding inventory by keeping up enough inventories, in the correct place and the perfect time at a lower cost to make the perfect measure of required items products. Given that, this study was conducted to examine factors that affect the of inventory control system in public organization, the case study of TANESCO Head Office was chosen for the study. The study focused to analyze factors which affect the performance of TANESCO on their inventory control system, specifically to analyze the way they record and manage their inventory, fund availability for inventory purchase and the skill/ knowledge among staff on the way inventory is managed and controlled. The research methodology used in this study during data collection include questionnaire which was designed and distributed among 182 TANESCO employees to respond on. Data were collected and analysed using factor analysis and regression model in SPSS software, the aim was to determine the relationship between variables as well as how these variables effect on the inventory control system. From the investigation it was discovered that, there is a significant relationship between independent and dependent variables. Documentation, timely fund availability as well as professionslism were found to be significantly affect the inventory control system. Inventory manegement system in public organization is mostly affected by how the organization handle its inventory records, the use of electronic system of documentation was adviced to be the most effective one and should be adapted by public organizations. Skill required to handle inventory also was found to be one of the crucial factor that affect inventory control system, fund availability also will help the organization to make annual procurement and hence reduce cost of handling and frequent procurement of stocks. Then, from these findings, the study recommended that, TANESCO as well as other public organization s should make sure that proper documentation mostly the computerized system should be adopted in order to properly manage their records on inventory management. Stock ordering should adhere to PPRA regulations for tendering and ordering of stock.