The multigene family for human gamma-crystallin has been assigned to chromosome 2 using rodent-human somatic cell hybrids and filter hybridization analysis of cell hybrid DNA. Two genomic DNA probes containing human gamma-crystallin gene sequences hybridize to five fragments in human DNA digested with the restriction enzyme EcoRI. By correlating the presence of these fragments in somatic cell hybrid DNA with the human chromosome content of the hybrids, at least six human gamma-crystallin genes can be mapped to chromosome 2. Data obtained with a hybrid clone containing a mouse-human interspecies translocation suggest that these genes may be clustered together on the long arm of human chromosome 2.