Purpose: The purpose of this study was to examine the causal relationships of perceived risk, satisfaction, switching cost and loyalty in outpatient health services. Method: A survey using a structured questionnaire was conducted with 393 hospital outpatients. The analysis of data was done with both SPSS Win 17.0 for descriptive statistics and AMOS 18.0 for structural equation model. Results: The causal model yielded Chi-square=31.44 (p=<.001), df=4, GFI=.98, AGFI=.87, CFI=.97, RMSR=.04, NFI=.96, IFI=.97 and showed relatively good fit indices. Perceived risk had a significant direct effect on customer satisfaction. Customer satisfaction, financial switching cost and relational switching cost had significant direct effects on customer loyalty. Perceived risk and customer satisfaction had significant indirect effects on customer loyalty. Conclusion: These results suggest that we should decrease the perceived risk and improve the customer satisfaction and switching cost to retain loyal customers. Further study with both a larger sample from various hospitals and a longitudinal design is necessary.