The nutritional benefits attributed to fish oils have been the basis for the study of the structural composition of Sardine oil triacylglycerols (TAGs). TAGs were separated reversed-phase high performance liquid chromatography (RP-HPLC) with the result of 65 chromatographic peaks resolved. The problem of identification was avoided by the use of two more chromatographic techniques. Separation of the sardine oil TAGs into fractions by silver-ion thin layer chromatography (TLC) and its subsequent fatty acid analysis by gas chromatography allowed identification of 59 of the 65 chromatographic peaks. From those peaks, the major was trimyristin (MMM), with 8.22 % of the total. Dioleoyl-acyl-glycerol (OPO, OOE), dipalmitoyl-acyl-glycerol (PPO, PPPo), dipalmitoleoyl-acyl.glycerol (PoPoO) and dieicosapentaenoyl-acyl-glycerol (EEP) species were found in important amounts.