C.difficile associated diarrhea (CDAD) is now considered to be one of the commonest causes of nosocomial diarrhea. CDAD, once considered to be a “nuisance” disease, has lately become a “killer” disease with appearance of a hypervirulent strain, toxinotype III. Although the incidence and severity of CDAD have increased in the western world especially in health care settings; it still is under-recognized in India and Asia. Any episode of diarrhea with fever and leucocytosis in a patient on some antibiotics in a health care setting is strong pointer towards presence of CDAD. Clinical suspicion is usually confirmed by ELISA based C. difficile toxin assays in the stool sample. The aim of therapy is to restore normal colonic microflora, resulting in the elimination of C. difficile. Treatment of C.difficile needs to be individualized depending on the severity of the disease and patient characteristics. Majority of patients will require antibiotic therapy and, whenever possible, discontinuation of the predisposing antibiotics. Metronidazole and vancomycin are the mainstay of the treatment of CDAD, as both these agents are highly active against all strains of pathogenic C.difficile. Neither of these drugs is however effective for the carrier state of C. difficile. Approximately 15%-30% of patients experience a symptomatic recurrence after discontinuation of antibiotics. Control of health care associated CDAD involves a range of primarily preventive measures including proper hand hygiene, use of personal protective equipment, environmental decontamination, isolation or cohort nursing and adequate treatment of CDAD cases.