Clinical and biochemical data were collected prospectively from 8032 jaundiced patients to form a database as part of a EU-supported project on computer-aided diagnosis. Patients were recruited prospectively from centres in all EU-countries and some other countries as well. Five hundred and twenty-eight jaundiced patients were collected from four centres in Denmark. Alcoholic cirrhosis, acute alcoholic liver disease and malignancy of the pancreas or the biliary tract were more common in the Danish data base: 49% of cases in Denmark as compared to 30% of cases in the international database. Viral hepatitis was underrepresented in Denmark, 16% as compared to 23% in the international group. A crude Bayesian diagnostic programme on the total database with 17 diagnostic groups achieved 63% accuracy. For the 528 Danish cases the diagnostic accuracy was 64% when the European data base was used, whereas it increased to 81% when only the Danish data base was taken as basis for the calculations. In conclusion, we found a drop in diagnostic accuracy for the Danish patients when using the large European data base instead of the national one.