Using the C-14 urea breath test we estimated the gastric urease activity among 46 healthy Norwegians, all employed at the section of gastroenterology, Haukeland Hospital, Norway. The overall prevalence of Helicobacter pylori-infection (30.4%) is similar to that reported previously among healthy subjects outside hospitals. The tendency towards higher prevalence among the gastroenterologists (41.7%) may be accounted for partly by the preponderance of males in this profession. The results do not support the notion that gastroenterologists are more liable to attract gastric H pylori-infection than other hospital personnel.