Mouse glandular kallikreins are encoded by a family of closely linked genes which are located on chromosome 7 at a site corresponding to the genetically defined Tam-1, Prt-4, and Prt-5 loci. We have characterized 24 kallikrein genes by genomic cloning and restriction mapping of 310 kilobase pairs of BALB/c mouse DNA. Most of these genes are highly homologous, have the same exon/intron organization, and are linked in clusters of up to 11 genes. Partial sequence analysis of the kallikrein genes has facilitated identification of those members of the family for which protein sequence data exist and assignment of those which are pseudogenes or encode proteins of unknown function. We find that a maximum of 14 mouse kallikrein genes have the potential to encode functional proteins.