While studies have found that greater job demands leads to greater burnout, there have been some inconsistent findings in the effects of demands. Building on Job Demands-Resources research and the challenge-hindrance framework, we investigate how (a) appraisals and (b) psychological needs satisfaction affect the relationship between job demands and burnout/engagement. A time-lagged online survey was conducted with 160 full-time employees across diverse locations and occupations (51.9% women, mean age was 30.0 years old, SD 7.14). The data was analyzed using multiple regression analysis. We found that some hindrance and challenge appraisals of job demands moderated the relationship between job demands (cognitive and emotional) and burnout/engagement, and satisfied psychological needs (relatedness and autonomy) moderated the relationship between job demands and engagement. This study extends existing research by investigating job demand appraisals and psychological needs as moderators of the job demands-well-being relationship and by partially explaining job demands’ relationship with positive and negative well-being outcomes.