Tricuspid valve endocarditis on a normal valve has been rarely documented in children. In all five previous cases the infecting organism was Staphylococcus aureus. We report five infants and children with tricuspid valve endocarditis, whose ages ranged from four months to four years. In all of them large vegetations were identified by two-dimensional echocardiography. Positive blood cultures were found in four of five patients. Staphylococcus aureus, Corynebacterium species, Haemophilus influenzae and Candida albicans were the respective isolates. There were three deaths, all relatively sudden, 10–33 days after commencement of antibiotic therapy. At the only post mortem carried out in the patient with Candida albicans endocarditis and Down syndrome, there were two large fungating masses straddling the tricuspid valve. They appeared to have obstructed the circulation. Microscopic examination of a lymph node and the thymus showed features consistent with an immune deficiency syndrome. One child has been lost to follow-up. In the remaining survivor, progressively severe tricuspid regurgitation with congestive cardiac failure, necessitated open heart surgery 13 months later. A homograft replacement of the destroyed septal leaflet was carried out. Tricuspid valve endocarditis in an infant or child is a serious and potentially lethal condition. Early surgical intervention to remove large obstructive vegetations appears to be warranted.