A self-emulsifying composition contains: 70 to 90% by weight in total of one or more compounds selected from the group consisting of ω3 polyunsaturated fatty acids and their pharmaceutically acceptable salts and esters; 1 to 29% by weight of an emulsifying agent selected from among a polyoxyethylene sorbitan fatty acid ester, a sorbitan fatty acid ester, a glycerin fatty acid ester and a polyoxyl castor oil; and 0.5 to 6% by weight of water when the composition is defined to be 100% by weight as a whole. The self-emulsifying composition is excellent in self-emulsifying property, composition dispersibility, emulsion stability, and absorbability, is free from ethanol and polyhydric alcohols or only has such an alcohol added thereto at a reduced concentration, and is useful for foods and pharmaceuticals.