The pharyngo-esophageal diverticulum (Zenker's diverticulum) has traditionally been treated operatively by an external approach. Since the 1950's the endoscopic technique has been performed increasingly as a good alternative. Since 1989, we have treated Zenker's diverticulum endoscopically as a standard procedure, and hereby we present our results here. We use the Benjamin-Hollinger diverticuloscope, through which the septum between the diverticulum and esophagus is divided by a CO2-laser. Nine patients have been treated, five men and four women. Mean age 77 years (range 59-93). Diverticulum size varied between 1x2 cm and 6x6.5 cm. No major complications occurred. One patient had recurrence of symptoms after three months and was reoperated with the same technique. The mean observation period is 12 months (range 4-28). We find the endoscopic CO2-laser technique safe, and for the elderly age group suffering from Zenker's diverticulum, less traumatic than the external approach.