The Fontan procedure is the final procedure in staged palliation for patients with functional single-ventricle physiology. The goal of the procedure is to separate systemic and pulmonary blood flow by directing systemic venous return through the Fontan connection to the pulmonary arteries and the lungs without ventricular contribution. Following the procedure, pulmonary blood flow is completely passive and dependent on pressure gradients, resulting in complex postoperative cardiopulmonary interactions. Understanding the physiology is essential to effectively manage these patients. Critical care nurses caring for patients after a Fontan procedure must understand preoperative data, risk factors, and unique postoperative physiology so they can anticipate specific postoperative problems, recognize trends in clinical status, and develop an appropriate plan of care. This paper reviews the first 2 stages of single-ventricle palliation, relevant modifications to the Fontan procedure, important preoperative cardiac catheterization data, common postoperative problems, and outcomes after the Fontan procedure.