Background: Congenital cardiac disease may be a chronic condition, necessitating life-long followup for a substantial proportion of the patients. Such patients, therefore, are often presumed to be high users of resources for health care. Information on utilization of resources in adults with congenital heart disease, however, is scarce. Methods: This retrospective pilot study, performed in Belgium, investigated 192 adults with congenital heart disease to measure the annual expenditures and utilization of health care and compared the findings with data from the general population. We also sought to explore demographic and clinical parameters as predictors for the expenditures. Results: Hospitalization was documented in 20.3% of the patients, with a median length of stay of 5 days. The overall payment by health insurance associations in 1997 was 1794.5 ECU per patient, while patients paid on average 189.5 ECU out-of-pocket. For medication, the average reimbursement and out-of-pocket expenses were estimated at 78 ECU and 20 ECU, respectively. Expenditures for patients with congenital heart disease were considerably higher than the age and gender-corrected expenditures for the general population (411.7 ECU), though this difference was accounted for by only one-eighth of the cohort of those with congenital heart disease. In general, higher expenditures were associated with abnormal left ventricular end-diastolic diameter, female gender, functional impairment and higher age, although the explained variance was limited. Conclusion: Our study has provided pilot data on the economic outcomes for patients with congenital heart diseases. We have identified parameters that could predict expenditure, but which will have to be examined in future research. This is needed to develop guidelines for health insurance for those with congenital heart diseases.