Pat O'Hare was the Executive Director of Harm Reduction International from its founding in 1996 until he stepped down in 2004. He was then Honorary President of IHRA from 2004 until 2011, when he was elected to the board of directors of Harm Reduction International (HRI), the new name of IHRA. His work has taken him around the world to advocate for harm reduction approaches to the problems caused by drug use, especially those caused by the sharing of injecting equipment. He has edited three books on harm reduction and has published extensively on HIV prevention, education and drug policy, and has spoken at many international conferences.