Purpose: The purpose of this paper is to analyze the effect of job stress on work impairment. Method: 354 workers' data from Seoul and the Gyeonggi area were collected between February 1 and March 30 2006 by structured questionnaire. The questionnaire was meant to determine demographic data, job stress, and work impairment questionnaire. Data analyzed by SPSS 12.0 and AMOS 5.0 program. Results: Job stress was ranked job demand, insufficient job control, organizational system, lack of reward, job insecurity, interpersonal conflict, and occupational climate. The work impairment of completing work was increased when the stress of insufficient job control, lack of reward, job insecurity, and occupational climate were increasing. The work impairment of avoiding distraction was increased when the stress of job demand, insufficient job control, organizational system, lack of reward, job insecurity, and occupational climate were increasing. The stress of job demand, lack of reward, job insecurity, and occupational climate had an effect on avoiding distraction. The stress of lack of reward and occupational climate had an effect on completing work. Conclusion: If employers manage job stress of job demand, lack of reward, job insecurity, and occupational climate, their business will benefit.