A genomic clone containing the human plasma glutathione peroxidase (GSH-Px) gene has been isolated using a rat plasma GSH-Px cDNA as a probe. The partial nucleotide sequence of the clone completely matched the sequence of the human plasma GSH-Px cDNA. The results of Southern blot hybridization indicate that the human plasma GSH-Px gene consists of at least 4 exons and 3 introns, and spans about 12 kb. RNA blot analysis demonstrated that the human plasma GSH-Px gene is expressed in the kidney.