This study is an empirical assessment of the impact of the drug decriminalization policy followed by Portugal in July 2001, on the price of illicit drugs.The analysis is performed using a difference-in-differences approach and the Synthetic Control Method in order to construct a synthetic control unit from a convex combination of countries.The results suggest that the prices of opiates and cocaine in the post-treatment period did not decrease in the sequence of the policy change.We conclude that the drug decriminalization policy seems to have caused no harm through lower illicit drugs prices, which would lead to higher drug usage and dependence.