A self-emulsifying composition which comprises, when taking the total amount of the self-emulsifying composition as 100mass%, 70 to 90mass% of at least one compound selected from the group consisting of ? polyunsaturated fatty acids, pharmaceutically acceptable salts thereof, and esters of the same, 0.5 to 6mass% of water and 1 to 29mass% of an emulsifying agent that comprises a polyoxyethylene sorbitan fatty acid ester (and that further contains a polyoxyl castor oil optionally, with the proviso that the emulsifying agent does not include lecithin) and which contains 3 to 40 parts by mass of lecithin relative to 100 parts by weight of the ? polyunsaturated fatty acid or the like. This self-emulsifying composition exhibits excellent self -emulsifying properties, composition dispersibility, emulsion stability and absorbability, and does not contain ethanol or a polyhydric alcohol or contains the same only in a low concentration. The self-emulsifying composition is useful for food and medicine.