In an open-label emergency-use study, 23 patients with bacterial infections caused by multiply drug resistant pathogens were treated with clinafloxacin. Efficacy and safety were evaluated by tabulating investigators' assessments at the end of treatment, treatment discontinuations and adverse event data. Most of the patients were seriously ill and had multi-organ infections, primarily respiratory tract infections such as nosocomial pneumonia and gastrointestinal infections. Eleven patients were successfully treated, two had treatment failure and 10 were not evaluable because the patients died of their underlying disease. Considering that most of the patients had several infections caused by multiply resistant pathogens, clinafloxacin may be useful for the treatment of such life-threatening episodes.