As the number of medical tourist continues to increase over the last decade, there is an emergent need to manage the medical tourism market. However, there is a lack of hard evidence to support growth in future. Thus, this research is to investigate the effect of perceived risk on the actual service experiences of medical tourists. The data was collected from 153 foreign patients who were admitted to the hospital between August and November, 2013 at four tertiary general hospitals and one general hospital, in either Seoul or Incheon. For the statistical analysis of data, hierarchical multiple regression analysis were implemented. The major results of this study are as follows: First, foreign patients chose word-of-mouth as the major information source for the purchase decision and also as the main method to reduce risk. Second, a positive attitude toward medical tourism significantly influenced on the perceived service quality. Third, perceived risk on through all purchase stages negatively influenced on perceived risk. In "pre-visit" stage, patients perceived more risks for financing and making an uncertain decision. Meanwhile, in "during-stay" stage, culture related(food, cultural differences and communication) and finance related(additional cost) were indicated as the major factors. For "post-discharge" stage, the medical side(recovery pain, side effect & complication) and the financial side(whole time and money invested, cost for follow-up care) were ranked in the top groups. Fourth, the risk reduction in the "pre-visit" stage significantly influenced on perceived service quality compared to other stages. This indicates that foreign patients perceive a high quality of service if they do more risk reduction activities before visiting the destination. The major risk reduction methods included gathering advice of friends and family, consulting with expert, direct trial and collecting information through formal source. The implications as follows were drawn from the results of this study. First, hospitals participating in medical tourism services should use experienced patients as marketers and the stories of their experiences as marketing tools. Second, the hospitals or governments should advertise both the excellence of the medical service and the subsidiary benefits of medical tourism. Third, reducing perceived risk of medical tourists should be managed in advance. Fourth, risk reduction activities should be induced before the patients visit.