Objectives: This study was conducted to identify the job characteristics and health status of sales and service workers at micro-enterprises. Methods: Multivariate analyses were conducted using data on respondents to the 5th Korean Working Conditions Survey who were business owners (7,572 persons) or employees (3,317) working in sales or service positions at micro-enterprises. Results: Among those analyzed, business owners were found to experience worse health conditions than employees. Business owners also differed from workers in terms of job characteristics. More than employees, they engaged in tiring or painful postures that negatively affected subjective health condition, experience of muscle pain, and experience of depression or anxiety. While employees' health was negatively affected by dealing with angry customers, the health status of business owners was negatively affected even by dealing with ordinary customers. Conclusions: These results show that the owners of micro-enterprises were in a more vulnerable state of health rather than their employees. In order to address this, it is necessary to correct work posture and reduce the stresses that come from customers.