The purpose of this study was to determine the mediating effect of organizational commitment on organizational cultural relations and person organization fit on employee performance. This type of research is quantitative research. This study takes the subject at Muhammadiyah Siti Aminah Bumiayu General Hospital. The sample of this study is the part of nurses, administration and midwives totaling 105 respondent. The sampling method in this study is the Sample Random Sampling. The data analysis technique used is multiple linear regression analysis test by using the SPSS 24 program. The results of data analysis show that organizational culture does not have a significant positive effect on organizational commitment. person organization fit has a significant positive effect on organizational commitment. Organizational culture has a significant positive effect on employee performance. person organization fit does not have a significant positive effect on employee performance. Organizational commitment has a significant positive effect on employee performance. Organizational commitment does not mediate the relationship of organizational culture to employee performance. Organizational commitment mediates the relationship of person organiztion fit to employee performance.