Fosfomycin is a relatively new antibiotic drug, deriving from streptomyces species. Its special chemical structure and small molecular size provide a very good diffusion into tissues like bone, fascia and wound exudates as well. In a clinical study Fosfomycin was given to 26 patients with infections mainly of the middle ear and mastoid as well as other ENT-infections. Clinical success, laboratory investigations and bacteriology are described in detail. The drug proved to be of special value in the treatment of chronic purulent otitis, purulent or chronic secreting tympanoplasties or other postoperative middle-ear affections when caused by penicillin-resistant staphylococci, proteus-species and pseudomonas aeruginosa. In the other cases treatment results were good corresponding to the bactericidal spectrum of Fosfomycin. There was one treatment failure in our series, but no reverse reaction at all.