Farming of Snakeskin gourami (Trichogaster pectoralis; Osphronemus) is one of the important farming activities in the Mekong Delta, Vietnam. In this study, we investigated the C and N isotope composition of the fish feeds and fish muscle to compare feeding habits of farmed fish with wild fish. It is assumed that the C and N sources for the Snakeskin gourami from farming ponds and water bodies in national park were different. It is presumed that farmed snakeskin gourami consumes pelleted feeds and zoobenthos. The results further suggest that rice bran contributed little to growth of the fish.