A technique is described that facilitates to identify and dissect the narrow communicating tract of the hernial sac in hydrocelectomy for communicating hydrocele. This method utilizes the blue dye that is injected into the distal sac and stains along the communicating´ tract so as to be identified without difficulty. We have used this technique on 10 difficult cases, which were extremely narrow or obliterated communicating tract and got the good results.