OBJECTIVE: Evaluation of drug expenditure and usage during last 13 years. METHODS: A retrospective study was done by statistical evaluation of drug files in Drug Administration archives. RESULTS: Statistics show that there are a 66.1% accumulating increase in drug consumption during last 13 years with an average increase of 5.1% annually. Since first of April 2002, an estimate of 20 billion numbers drug has been used in Iran, which is compatible with drug production increment (5%). During last 13 years, the average rate of domestic and imported drugs was 95% and 5% respectively. Drug consumption per capital in 2002 was 314 units per capital while this number was 144.6 in 21 years ago. Increase in drug consumption per capital is 43.6% while the money usage per capital shows 421% increment. CONCLUSION: Before year 2000, products costs were low because they were subsidized by the government while after that a new system is established in such way that insurance pays for the difference preserving the real price of the product.