Abstract: Ten years ago, Portugal launched an experiment that few countries had dared to try: the decriminalization of drug possession and use, including for drugs labelled by some countries as “hard,” such as cocaine and heroin. These changes to Portugal’s drug law and national policy have marked a turning point for the country and a milestone in international drug policy. Instead of seeking to diminish use by punishing users, the new measures consider drugs illegal but no longer treat drug consumption as a criminal offense. The changes are also particularly significant for Portugal, a conservative country marked by a history of fascistic governments and a Catholic Church that has a powerful influence on politics and social life. Portugal’s reforms have not been limited to treating drug possession as an administrative offense; they also include a wide range of measures such as prevention and social education, discouraging people from further use of controlled substances, harm reduction, treatment for drug dependent people, and assistance in reintegrating them into society. Contrary to initial concerns regarding Portugal’s new strategy, studies have shown that the number of drug users has not risen dramatically, and has even fallen in certain categories. In addition, the number of people with drug-related diseases (such as HIV and hepatitis B or C) has decreased overall. According to Portuguese and international experts, these positive trends are rooted in a drug policy that offers treatment to people who are drug-dependent, instead of treating them like criminals. Levels of drug consumption in Portugal are currently among the lowest in the European Union. Although new policy activities are often subject to internal debates and disputes, mainly concerning economic costs, the policy of decriminalization and the philosophy behind it have not given rise to any real controversy. They are based on a consensus among politicians and Portuguese society as a whole. The effects of Portugal’s experiment with drug policy have been corroborated by research, and the Portuguese people’s reactions to it have been verified by reliable surveys; this experience can and should be a lesson for a world caught up in a failed “war on drugs.” The innovative nature of the Portuguese approach proves that it is not generals, police officers, or criminal court judges, but rather doctors, social workers, and researchers who need to address drug-related issues.