Illegal drugs should be decriminalised, delegates at the Plaid Cymru conference have said.
Party members called the war on drugs an "unmitigated failure" and said criminalising those with an addiction does "nothing to help them turn their lives around".
Activists voted for decriminalisation to become party policy on Friday.
The party has four MPs in Westminster, where drugs policy for England and Wales is controlled.
Portugal decriminalised drugs in 2001.
