The cDNA for human cytosolic platelet-activating factor acetylhydrolase (PAF-AH) gamma-subunit was isolated and the gene structure was elucidated. The complete amino acid sequence deduced from cDNA contains 231 amino acid residues. Southern blot analysis indicated the presence of a single gene. Northern blot analysis showed that 1.0 kb transcript was expressed in a tissue specific manner. Comparison of the expression pattern between adult and fetal tissues suggests that the enzyme plays an important role during the development of brain.