Two new cases of ventricular tachycardia (VT) in the infant are reported, and reviewed in the light of the 23 case histories found in the literature. The diagnosis rests upon eliminating a pre-excitation syndrome, which is so common in this age group. The VTs found in infants are rapid, irregular, and take many different forms. They often necessitate urgent treatment with electric shocks. Preventive treatment consists of a combination of procainamide and beta-blockers in relatively large doses. The search for an aetiological agent should include a haemodynamic and angiocardiographic study of all the chambers of the heart to exclude cardiomyopathy, tumours, papyraceous right ventricle and congenital heart defects. Where no cause can be demonstrated, preventive treatment should be given, with regular electrical testing and other follow-up investigations. An attempt to reduce the drug dosage should be made every 6 months, in hospital. In cases which prove resistant despite adequate treatment, it seems justifiable to carry out a pericardial exploration with the aim of diathermising the ectopic focus; this approach is suggested because of the poor natural history of this type of case.