In a general practice database containing data on 62,000 patients, those with intellectual disability (ID) were traced. Health problems in this database were recorded according to the International Classification of Health Problems in Primary Care (ICPC) code. By using selected codes, 318 people with ID (0.65% of the study population) were found; the sample contained nearly as many false positives. Adding up the percentage of people with ID living in residential facilities, the total prevalence of people with ID was estimated as 0.82%. Documentation on the cause and level of ID was available in about half of the cases. The demographic characteristics of the people with ID were significantly different from the general population: there was a higher percentage of males and a lower percentage of people over 50 years of age among those with ID. Information about the use of home care was virtually non-existent in the general practice data. The results are compared with those of other studies. The discussion deals with reasons for complete documentation of cases with ID in general practice and the role of the general practitioner in health care supply to people with ID.