This study aims to develop a model of the relationships among medical service quality, patient satisfaction, organizational commitment and complaint behavior. Medical service quality is associated with patient satisfaction. Greater satisfaction of the patient with the service provided is associated with stronger affective or continuous commitment, and a lower probability of complaints to others. Moreover, the results indicate that patient satisfaction mediates the indirect effect of medical service quality on commitment and complaint behavior. These findings suggest that improving medical service quality can generate significant differential performance, especially when patient satisfaction is considered.