Sodium fusidin prepared at the All-Union Research Institute of Antibiotics was studied experimentally and clinically. High antibacterial activity of fusidin especially against methicillin-resistant staphylococci was found. The clinical trials showed high efficacy of fusidin in treatment of perichondritis, osteomyelitis, pyodermia, pseudofurunculosis, multiple abscesses of the skin because of its satisfactory penetration into the skin and cartilage tissues, skin and subcutaneous cellular tissue. The tolerance of the drug by most of the patients was satisfactory.