Endocarditis of transvenous pacing leads is a rare condition. The authors review a series of 15 patients who developed bacteriologically proven septicaemia and/or endocarditis related to transvenous pacing leads, operated between 1988 and 1993. The interval between the last manipulation of the pacemaker and the onset of endocarditis was about 6 months. Six patients had had haematoma and/or infection of the pacemaker site. Endocarditis presented with chronic pyrexia (14 cases) associated with septicaemia (6 cases) and chronic local suppuration (1 case). The interval between the beginning of the pyrexia and the diagnosis was 3.4 months. Echocardiography showed a mass attached to the pacing lead in 8 cases and tricuspid valve vegetations in 4 cases. Blood cultures were positive in 13 patients and local wound swabs identified the organism in 1 patient. The commonest causal agent was the staphylococcus (epidermis in 7 cases, aureus in 4 cases). Appropriate antibiotic therapy was only effective in 1 case. The surgical indication in 13 cases was persistence of infection associated with pulmonary embolism (3) or tricuspid regurgitation (2). Complete ablation of the prosthetic material was performed by a peripheral vascular approach (2 cases), by a right atrial approach (1 case) and under cardiopulmonary bypass in 12 cases. The peroperative findings were of tricuspid valve vegetations (4 cases), thrombi on the pacing lead (7 cases) or in the right heart chambers (2 cases) or pulmonary artery (2 cases). The associated procedures performed under cardiopulmonary bypass were tricuspid valve repair (2 cases) and pulmonary thrombectomy (2 cases). Temporary and permanent epicardial leads were implanted in 10 patients.(ABSTRACT TRUNCATED AT 250 WORDS)