Yaws was a significant health problem in Papua New Guinea until the nationwide total mass treatment campaign, which took place from 1953 to 1958. The number of cases reported annually fell to less than 300 during the 1960s. In the early 1970s outbreaks occurred in East New Britain and Bougainville but were effectively controlled. A larger outbreak in 1977-1978 on Karkar Island was more difficult to bring under control despite the clinical appearance of the cases, which were less florid than those seen in the 1950s. The latter outbreak raised questions about decreased response to penicillin, lack of ability to develop effective immunity, and increased susceptibility to yaws. Smaller outbreaks were reported in 1983 and 1984 in remote areas, but the current extent of yaws in Papua New Guinea is not fully known. Action is being taken to rectify this situation and to ensure that reports of yaws are fully investigated and that cases are properly managed.