Biofilms are bacterial communities ubiquitous to moist environments. Biofilm formation is a factor in the development and persistence of infectious diseases. In clinical nephrology, biofilms influence the development of kidney stones and affect dialysis systems, including peritoneal and central venous catheters. Biofilms also play critical roles in persistent and resistant renal and urinary tract infections.To describe the physiology of biofilms and potential effects of biofilms upon infectious diseases, focusing on the role of biofilms in kidney stones, indwelling catheters and dialysis equipment.A literature search with Medline to identify pertinent English language articles published up to early 2008 using the keywords biofilm, nephrology, renal, calculi and infection.Biofilms are ubiquitous in clinical nephrology and play a role in the pathogenesis of resistant infections. Strategies for reducing the effects of biofilms in nephrology are described.