Vertebrate sarcomeric myosin heavy chains (MHC) are encoded by multigene families whose members show tissue-specific and developmentally-regulated patterns of expression. Molecular genetic studies have allowed the cloning of a small number of complete genes or cDNAs encoding MHC isoforms [see Warrick and Spudich, Annu. Rev. Cell Biol. 3 (1987) 379-421]. Reported here is the isolation and sequence of a 2.6-kb cDNA that encodes the subfragment 1 or head of a human perinatal skeletal MHC. A cDNA sequence encoding the rod portion of this isoform has been previously reported [Feghali and Leinwand, J. Cell Biol. 108 (1989) 1791-1797]. Polymerase chain reaction with fetal skeletal muscle RNA was used to join the two nonoverlapping cDNA sequences to construct a full-length sequence. The gene encoding the perinatal skeletal MHC has been localized to the cluster of skeletal MHC-encoding genes on chromosome 17.