Objective: To evaluate job participation, careerrelated problems, and actual job problems in adults with complex congenital heart disease (CHD) compared with adults with mild CHD and reference groups. Design: Cross-sectional study. Setting: Patients were randomly selected from the archives of the Department of Pediatric Cardiology, Leiden University Medical Center, Leiden, the Netherlands. Patients and Main Outcome Measures: In total, 76 patients with complex CHD and 80 with mild CHD (age range, 17-32 years) completed a self-reported questionnaire on employment and handicaps, with reference data available (response rate, 70%). Results: In the study groups, 45 (59%) of 76 patients with complex CHD had a paid job compared with 61 (76%) of 80 patients with mild CHD. Patients older than 25 years with complex CHD had significantly lower job participation (64%) than the general population (83%). Multiple logistic regression showed that type of CHD and level of education were significantly and independently related to job participation (odds ratio, 4.8; 99% confidence interval, 1.2-19.6; and odds ratio, 4.7; 99% confidence interval, 1.3-17.2, respectively). Of the 76 patients with complex CHD, 42 (55%) experienced diseaserelated career problems, in contrast to only 1 patient with mild CHD. Both CHD groups had more job-related mobility handicaps than did the reference group. However, in the mild CHD group, handicaps could be attributed to additional noncardiac diseases. Conclusions: Patients with complex CHD have reduced job participation compared with patients with mild CHD and the general population. Many receive disability benefits or experience career problems or job handicaps. Career counseling focusing on physical abilities and level of education may help prevent or reduce these jobrelated problems.