Fasting plasma cholesterol, triglycerides and uric acid were measured in 109 Melanesian residents of Port Moresby and 71 residents of a Papuan coastal village. Cholesterol and triglyceride levels were low, mean cholesterol 3 . 74 and 3 . 70 mM/l and triglycerides 0 . 64 and 0 . 59 mM/l respectively in urban and rural residents, with no relation to age or sex. Uric acid was higher in urban men (0 . 37 mM/l) than either urban women (0 . 26 mM/l) or rural men and women (0 . 25 and 0 . 24 mM/l). The levels of plasma cholesterol found in this study are similar to previous reports on rural populations in Papua New Guinea. The apparent failure of plasma lipids to increase significantly in urbanised residents of port Moresby who had a significantly higher prevalence of both diabetes mellitus and obesity is unexplained.