This study analyses the results of cardiac pacing in 241 children operated between 1965 and March 1982 in 9 french cardiac centres. The ages at primary implantation were: less than 5 years, 32.8 p. 100, 6 to 10 years, 33.6 p. 100 and 11 to 16.5 years, 33.6 p. 100. Atrioventricular block was congenital in 40.7 p. 100 of cases (98 children) and postoperative in 56.4 p. 100 (136 children) with 67 cases, after repair of isolated ventricular septal defect and 18 after repair of an endocardial cushion defect. The symptoms preceding pacing were syncope (67 cases), bradycardia (92 cases) and cardiac failure (33 cases). The electrocardiographic indications were third degree block in 66.8 p. 100 of cases. The pulse generators were usually implanted in the abdominal wall (71.8 p. 100). The power sources in service (August 1982) were lithium (74 p. 100) and isotopic batteries (26 p. 100). Myocardial electrodes were used in 93.4 p. 100 of cases; 82.2 p. 100 were made by Medtronic. Early problems included: infection (10 cases), displacement of endocavitary electrodes (3 cases), elevated thresholds (2 cases). The late problems encountered were due to fracture of the pacing electrodes (19 cases) and elevated thresholds (50 cases). Two hundred and seven children are alive and well. A total of 341 pulse generators were implanted, 90 p. 100 being VVI mode. In August 1982, 56.6 p. 100 were programmable or multiprogrammable. Despite the technical problems involved, the myocardial approach is still used with good results, especially in young children and babies. The endocavitary approach is an alternative after 5 years of age.(ABSTRACT TRUNCATED AT 250 WORDS)