The use of catheters in the urinary tract, both in children and adults, has not been without complications. Many procedures performed in the urinary tract, including urethral or suprapubic catheterization of the bladder, urethrography, and ureteral catheterization, have showed complications, one of which is the formation of catheter knots. This complication, although very rare, yet it is very annoying. In this study, we searched (in winter 2002, employing Medline) and reviewed published reports of urinary tract catheter knots, and present measures for prophylaxis, diagnosis and proper management of this rare complication.