Infections remain among the major causes of disease, hospitalization and death in uremic patients, especially in those treated by dialysis. Several pathophysiologic factors enhance this infectious risk: (1) breakdown of protective barriers; (2) affinity of bacteria for foreign materials; (3) bioincompatibility; (4) uremic toxin retention; (5) deficiency and resistance to vitamin D; (6) carriership of germs, and (7) malnutrition. Twenty to 30% of dialysis patients develop infection, and 20-30% of these die from their infection. Sepsis is significantly more frequent, and mortality secondary to sepsis is 50 times higher than in the normal population. Bacteremia (prevalence 1 episode/100 patient-months) is mainly caused by Gram-positive species, especially in vascular access-related infection and infection of unknown origin. Among these Gram-positive germs, staphylococci play a predominant role. The most frequent and most morbid viral infections are associated with hepatitis. Whereas the incidence of hepatitis B decreases, hepatitis C has become the major variant. The incidence of tuberculosis has increased up to 15 times, and in the Western world it mainly affects patients who immigrated from endemic areas. Fungal infections are also frequent, especially in the setting of peritoneal dialysis. In conclusion, infections remain a frequent and morbid problem in dialysis patients. Preventive measures should be applied more vigorously. Copyright 2002 S. Karger AG, Basel