Abstract A full-length cDNA encoding mouse annexin V (ANX5) was cloned, sequenced, and utilized for chromosomal mapping. The gene lies on mouse chromosome 3 in close linkage with the fibroblast growth factor 2 (basic) gene and is syntenic with other genes known to have orthologous counterparts on human chromosome 4q. The open reading frame encoded a protein of 319 amino acids (aa), with 92–96% identity to ANX5 in other species. Internal repeat 3 of mouse ANX5 exhibited the highest level of nonconservative aa replacements with respect to other annexin subfamilies, but the greatest sequence conservation among ANX5 species members. This region may thus contain features that distinguish ANX5 from other annexins in properties or function. Phylogenetic analysis and homology testing of ANX5 members indicated that the 34-kDa annexin from Torpedo marmoratamay also belong to this subfamily. Comparison of nine species of ANX5 led to an estimation of the unit evolutionary mutation rate at 1% aa replacements every 8 million years, comparable to other annexins.