Fosfomycin is an antimicrobial substance which is available since several years. In earlier clinical studies an oral preparation with poor absorption in a low dosage resulted in inadequate therapeutic results. The presently used parenteral administration in a dosage range of up to 250 mg/kg BW however allowed us to appreciate several unique properties of this drug which make it valuable in the treatment of serious bacterial infections. Due to its small molecular weight and complete lack of protein binding a favorable penetration in tissues and deep compartments (e.g., meninges, bone, heart valves) was observed. In addition fosfomycin shows a remarkably low toxicity and even protects from the nephrotoxigenic effects of aminoglycosides and other drugs. Earlier problems in antimicrobial susceptibility testing have been solved by addition of glucose 6 phosphate into the growth medium. Fosfomycin, the first representative of a completely new class of antibiotics does not show cross-resistance with other antibiotics; therefore pathogens of nosocomial infections, particularly methicillin- und gentamicin-resistant staphylococci are mostly susceptible to this antibiotic. Clinical investigations show a favorable therapeutic outcome in severe nosocomial infections despite of previous therapeutic approaches with various other potent antibiotics. In an international symposium in Mexico City the available clinical experience with this drug was presented and indications for the use of this antibiotic were established. Prof Dr. K. H. Spitzy Contents Summary-Zusammenfassung ......................................................... .