Policymakers in developing countries are looking for effective and efficient ways to control hiking expenditure on medicines. This article shows the effectiveness of the ABC-VEN method to improve efficiency in resource use with data from Mwananyamala hospital in Tanzania. We used expenditure data for 233 medicines worth 909.9 million Tsh (392,386.4 USD) bought in the year 2018/2019. Data were extracted from the electronic system, receipts, and other relevant documents. Medicines were categorized according to their contribution to the total medicine expenditure (ABC) and their importance to the functioning of the hospital (VEN). 39 (17%) medicines belong to group A and 134 (57%) to C, which accounted for 70% and 10% of the total medicine expenditure, respectively. 15%, 78%, and 7% of the medicines belong to the Vital, Essential, and Non-essential groups, respectively. 65 medicines (28%) that accounted for 73% of the total medicine expenditure were in group I that requires stringent control. 4 high-cost non-essential medicines and 20 low-cost vital medicines accounted for 7% and 1% of the total medicine expenditure, respectively. Efficiency can be improved through rational prescribing and substituting high-cost non-essential with low-cost vital medicines.