The purified preparations of Klebsiella bacteriophages, viz. the monovalent preparation of K. pneumoniae bacteriophage and the polyvalent bacteriophage preparation for the treatment of infections caused by K. ozaenae, K. rhinoscleromatis scleromatis and K. pneumoniae sensu lato, have been obtained. The bacteriophage preparations have proved to be nontoxic and safe for laboratory animals after the intraperitoneal injection of these preparations followed by the pathomorphological study of the internal organs of the animals. The clinical study of the newly developed bacteriophage preparations in the course of the treatment of purulent inflammatory diseases in 109 patients has revealed that the preparations are not reactogenic and exhibit sufficient effectiveness in the therapy of ozena, rhinoscleroma and Klebsiella infections with different localization of the infectious process.