The tetrazole ring is an important pharmacophoric moiety. It is a structural part of many pharmaceutical drugs, drug candidates (or lead compounds), and various biochemical reagents. This review summarizes data of the last 10-15 years on the use of tetrazoles in biomedicine and the views on the mechanism of their biological action. The prospects for the development of new biologically active substances containing a tetrazolyl pharmacophoric moiety are analyzed. Bibliography — 263 references.