Purpose: The purpose of this study was to identify factors associated with the mental health-related quality of life (MHQoL) of Korean workers. Methods: This was a cross-sectional study of 192 Korean pay workers who worked in the Daegu and Gyeongbuk Province, Korea. Data were collected from May 15 to July 2, 2019, through self- reported questionnaires. The survey had a total of 87 questions including individual, organizational, and psychosocial factors. MHQoL was measured using short form-36 version 1. Data were divided into four domains of MHQoL and analyzed using a hierarchical linear regression model. Results: From the hierarchical linear regression analysis, when the psychosocial factors were included in the regression model, the R² change in the four domains of MHQoL increased significantly by 19~47%. A common predicting factor associated with the four domains of MHQoL was identified as perceived stress symptoms. Other factors affecting MHQoL showed slight differences in each domain. Conclusion: Based on the study results, it is necessary to monitor the psychosocial symptoms to improve MHQoL of Korean workers. Considering each factor affecting the four areas of MHQoL, workplace-based interventions to improve MHQoL should be provided to workers.