The SGK protein kinase is a novel member of the serine/threonine protein kinase family. Its corresponding gene belongs to the group of immediate-early genes. SGK transcription is controlled by cell volume alterations in different cell lines. To analyze the genomic structure and chromosomal location of the SGK gene, a human P1 clone was isolated by screening a human genomic library with a SGK cDNA probe. This clone was confirmed to encode the authentic SGK gene by the detection of exon-intron structures and the correspondence between the nucleotide sequences of exons and human cDNA. Using this P1 clone as a probe for fluorescence in situ hybridization, a single chromosomal locus for SGK was assigned to band 6q23, a region frequently affected by deletion in various human neoplasms.