Neurally adjusted ventilatory assist (NAVA) is a form of partial ventilatory support wherein the machine applies positive pressure to the airway opening throughout each inspiration. In contrast to all other modes of ventilation, which adopt conventional pneumatic signals (flow, volume, and airway pressure) to drive and control the ventilator operation, NAVA utilizes the electrical activity of the diaphragm, which is the best available signal to estimate the respiratory drive and to trigger on and cycle off the delivery of the mechanical assistance and regulate its amount and intra-breath profile. With NAVA, therefore, the patient retains full control of the breathing pattern. Following the first description of NAVA ten years ago, various studies have been performed on this mode of ventilation, either in animal models, healthy subjects, or in adult and pediatric critically ill patients. These investigations indicate that this novel mode is efficient in unloading the respiratory muscles and maintaining adequate gas exchange while improving the patient-ventilator interaction. This review article aims to summarize the results of the studies published to date on this topic.