A decline of the sport fishery for salmon has been associated with the application of DDT to control human insect pests around the shores of Sebago Lake. The average DDT contents of 10-salmon samples collected in 1962, 1963, and 1964 were 1.1, 3.2, and 1.8 ppm by total wet weight. Salmon belonging to age group III had average DDT contents of 1.2 ppm; age group IV, 8.0 ppm; and age group V, 8.8 ppm. Ovaries of III-year-old salmon had 0.87 ppm of DDT, while ovaries from IV- and V-year-olds had 6.0 ppm DDT. Data also include results of DDE assays and calculated DDT concentrations in the fat. DDT concentrations found in small samples of lake chubs, common shiners, smallmouth bass, American smelt, lake white-fish, and brook trout are also reported.