This article investigates the effects and the relative importance of the four perceived service quality dimensions on corporate image, customer satisfaction, and customer loyalty. To obtain results, factor analysis and multiple regression techniques are applied to data collected from 500 Thai outpatients of the five largest private hospitals in Bangkok. The findings indicate that the four dimensions significantly affect corporate image, customer satisfaction, and customer loyalty. More specifically, the doctor concern dimension is the most important factor affecting customer satisfaction and customer loyalty. The tangibles dimension is the most important factor affecting corporate image.