Lymphoblastoid cell lines established from two individuals with apparently balanced translocations involving 11p13 were used for LDHA regional localization. The karyotypes were 46,XY,t(4;11)(q21;p13) and 46,XY,t(1;11) (p22;p13). In situ hybridization of a human LDHA cDNA probe to chromosome preparations from these cell lines resulted in specific labeling over bands p14→p15 of the normal chromosomes 11 and over bands 11p14→11p15 of the derivative chromosomes 4 and 1. These results exclude LDHA from any region proximal to 11p13 and localize the gene to 11p14→11p15. © 1986 Springer-Verlag.