This article examines the technical modalities of ureteric catheterization. The authors also discuss non-conventional modalities which, when they are used without prejudice, can sometimes constitute brilliant and economic solutions to complex problems, which are often impossible to solve otherwise. After a summary of the history of ureteric catheterization, the authors present the main indications for temporary ureteric catheterization, which are: fluoroscopic and radiographic assessment of the organ; separate cytological harvesting; separate bacteriological harvesting; confirmation of the side of haematuria; temporary dilatation of the ureter prior to ureteroscopy; temporary drainage of the excretory tract after endourological investigation.. Finally, the authors describe particular situations that may be verified during temporary or even permanent catheterization, for example in the case of procedures in children, pregnant women and renal transplant recipients.