Pediatric echocardiography as performed and interpreted by pediatric cardiologists provides details of cardiac structure and function as well as hemodynamic data. Functional echocardiography, in contrast to echocardiography as performed by the cardiologist, is the bedside use of cardiac ultrasound to follow functional and hemodynamic changes longitudinally. Data reflecting cardiac function and systemic and pulmonary blood flow in critically ill preterm and term neonates can be monitored using this method. Functional echocardiography is being developed and driven by neonatologists as an extension of their clinical skills. A wealth of hemodynamic information can be derived from functional echocardiography used for the sick neonate, which provides clinical information different from the assumed underlying physiology. Lack of access to appropriate training programs and interdisciplinary politics is limiting the use of this potentially valuable clinical information. Without the use of functional echocardiography, clinicians are left to speculate as to the underlying pathophysiology of circulatory compromise, and the assumptions they make often are incorrect. For functional echocardiography to fulfill its clinical potential, it needs to be available at any time and at short notice in the neonatal intensive care unit (NICU). Because most NICUs do not have external diagnostic services to provide longitudinal hemodynamic follow-up assessment at the bedside, neonatologists should be able to develop appropriate echocardiographic skills in close collaboration with their cardiologist colleagues.