Cognitive achievement, behavioural problems, and various dimensions of personality were assessed in 48 male and female patients with congenital heart disease (CHD) aged from 12 to 16 years in comparison to a control group. The CHD group showed a lower speed of cognitive processing but seemed to have less state-anxiety and to possess a higher superego strength. Male adolescents with CHD presented with a reduced perceived capacity and self-esteem. This was not true for adolescent girls with CHD. The negative self-concept of boys with CHD may be partly explained by reduced physical ability interfering with peer relationships.