This study investigated the effect of healthcare inventory management practices on the performance of pharmaceutical companies in Rwanda with special focus on selected retail pharmacies located in Gasabo District. This research adopted a descriptive design to describe healthcare inventory management practices most used in retail pharmacies setting and a multivariate regression analysis to determine their effect on retail pharmacies performance. This study targeted a population of 195 respondents where all responsible pharmacists were selected to take part in it, unfortunately only 142 respondents took part in it and the data were collected using a questionnaire of both open ended and close ended questions. Then after, data gathered were processed and analyzed based on objectives to test the hypothesis. The study revealed that retail pharmacies in Rwanda employ a variety of approaches in managing inventory where the Economic Order Quantity (EOQ) method was the most widely used at 46.3%, indicating a focus on cost-effective inventory management. The majority of respondents strongly agreed that inventory control techniques were effective in reducing stock outs, maintaining appropriate inventory quantities, minimizing wastage and losses. Inventory shrinkages, such as expiration, damages, theft, and stock outs, significantly impact pharmacy performance, so emphasizing on addressing these issues through good inventory management would improve the performance effectively. The use of various stock management software systems was also examined, with Ishyiga being the most widely adopted system. These findings suggest that effective inventory management is essential for pharmacy performance, with technology adoption playing a pivotal role in enhancing efficiency and accuracy. The study also highlights the importance of addressing inventory shrinkages and utilizing various inventory control techniques. Therefore, inventory management practices play a crucial role in enhancing various aspects of pharmacy operations.