Clostridium difficile(C. difficile) is the most common cause of antibiotic-associated diarrhoea, usually occuring during the hospital care. C.difficile-associated diarrhoea belongs to a spectrum of clinical entities associated with C. difficile infection, CDI; aside from diarrhoea, infection can remain symptomless or it can lead to other conditions, such as pseudomembranous colitis or, rarely, fulminant colitis and sepsis. Risk factors for the disease include older age, severe chronic conditions, long hospital stay and association with other healthcare facilities.C. difficile is omnipresent in the environment (in soil, water and animals) with a part of population being asymptomatic carriers; the bacterium can be isolated in 40% – 60% of infants and 2% – 4% of adults. The main inciting factor for the infection is the alteration of normal gut flora caused by the use of antibiotics. Virtually any antibiotic can lead to C. difficile infection, but the risk is highest with the use of cephalosporins, penicilins, clindamycin and recently, fluoroquinolons. In such altered environment, the microorganisms thrive and produce toxins which damage the intestinal mucosa leading to fluid secretion and diarrhoea, and in more severe cases plaques called pseudomembranes form on the surface of the intestine. Diagnosis is based on detection of clostridial toxins in the stool and symptomatic patients are treated with oral metronidazole or vancomycin. The implementation of infection control measures is essential to reduce the spread of infection among patients and healthcare workers.