During the last years the study of fatty acids belonging to omega 3 family in marine foods has been emphasized due to their beneficial effects on cardiovascular diseases, which are the main cause of death in occidental countries, as described by literature. In order to obtain more information about the fatty acid composition of the main marine species fat constituent, usually consumed by Eastern Island population, seven fish species were analyzed: Maito (Acanthurus leucopareius), Matuko (Bodianus vulpinus), Marau (Myripristis tiki), Nanue (Kiphosus bigibus). Moki (Mori and Marari, Anampses caeruleopunctatus), Puia (Girellops nebulosus) and Raea (Cheilodactilus plessisi). Fatty acid profile and proximate analysis were determined for each species. According to its fat content, Nanue and Marari showed the highest lipid percentage, with values of 2.8 and 3.6% respectively. Fatty acid profile expressed as methyl esters percentage indicated that the most important group was that of the saturated fatty acids (SFA 35.1-54%), followed by the polyunsaturated fatty acids group (PUFA, 22-42.5%). Palmitic acid was the most important between saturated fatty acids, while oleic acid was the main fatty acid between the monounsaturated group. In omega-3 family fatty acids, eicosapentaenoic acid (EPA, C20:5w3) and docosahexaenoic acid (DHA, C22:6w3) were the most important, with values in a range between 2.0-12% and 1.8-18.3%, respectively. Omega-6 family showed a higher content in arachidonic acid (AA, C20:4w6) with values between 1.9 and 10%. Considering the fatty acid composition and the fat content, Marari was the highest in w-3 and w-6 fatty acid contribution, with values of 850 and 240 mg per one hundred grams of edible portion respectively.