Cannabis has been decriminalized in the state of Arizona If you are wondering if cannabis has been decriminalized in the state of Arizona, the answer is YES. Arizona is actually one of the more than 20 US states today that have implemented medical cannabis laws.Here is some more information on the cannabis legalization in Arizona: "Arizona Medical Marijuana Act" - Ballot Proposition 203, also known as the "Arizona Medical Marijuana Act", was approved on November 2, 2010, after getting 50.13% ...