Improved surgical techniques and instrumentation may facilitate an aggressive approach in correcting lower urinary tract abnormality in one stage in seriously ill children, but nevertheless be complicated and dangerous. Temporary diversion is still being used by some as a life-saving procedure as well as for salvage of the kidneys initially. Pelvi-uretero-cutaneostomy en-Y (PUC en-Y) has been proved to be a very useful approach with some advantages over the other temporary drainage procedures. The clinical material, indications, results and modifications are discussed. Reference is made to a case illustrating the potential danger of loop ureterostomy.