In 2000, the city of Hafnarfjörður, Iceland, implemented Parent Management Training--Oregon Model (PMTO(™)) to prevent and treat behavioral problems among children. This paper describes the implementation and findings regarding impacts in the community. As hypothesized, findings showed that the number of referrals to specialist services decreased in Hafnarfjörður following PMTO implementation and increased in two comparison communities not implementing the method. Within the Hafnarfjörður community, recorded instances of behavior problems reduced in elementary schools working in line with PMTO. The results presented are the first such findings in Iceland and suggest the kinds of systematic changes communities may experience following the implementation of an evidence-based program.