The Fellowship Program of the Department of Cardiology at Boston Children’s Hospital seeks to train academically oriented leaders in clinical care and laboratory and clinical investigation of cardiovascular disease in the young. The core clinical fellowship involves 3 years in training, comprising 24 months of clinical rotations and 12 months of elective and research experience. Trainees have access to a vast array of research opportunities – clinical, basic, and translational. Clinical fellows interested in basic science may reverse the usual sequence and start their training in the laboratory, deferring clinical training for 1 or more years. An increasing number of clinical trainees apply to spend a fourth year as a senior fellow in one of the subspecialty areas of paediatric cardiology. From the founding of the Department to the present, we have maintained a fundamental and unwavering commitment to training and education in clinical care and research in basic science and clinical investigation, as well as to the training of outstanding young clinicians and investigators.