Background: The purposes of this study is to analysis the differences of the job satisfaction between regular and non-regular workers in hospitals. Methods: The samples used for data analysis are 632 workers of 6 hospitals using a standardized questionnaires in B, C, D, and G provinces. In research methodology, all the data were analyzed with descriptive statistics, t-test, Pearson’s correlation, and multiple linear regression analysis. Results: In case of regular workers, communication, working conditions and employee benefit, and education were found to have a significant positive (+) effect on job satisfaction. In case of non-regular workers, empowerment, reward systems, communication, working conditions, and employee benefit had a significant positive (+) effect on job satisfaction. Conclusion: These results showed that hospitals needed to reinforce communication, working conditions and employee benefit to regular and non-regular workers in order to improve job satisfaction. Especially, more empowerment, working conditions, and employee benefit should be given to non-regular workers.