Recent studies have given attention to and have investigated factors that moderate the effect of emotion regulation strategies. This study examined whether cognitive appraisal of a situation moderates the relationship between cognitive emotion regulation strategies and psychological health via a one-week longitudinal study. At Time 1, participants were asked about the most stressful situation at that time and how they appraised it. At Time 2, they were asked what kind of cognitive emotion regulation strategies they used during the previous week to cope with the stress. The result indicated that when centrality, which is a factor of cognitive appraisal, was high, rumination and catastrophizing predicted higher anxiety, whereas when centrality was low, blaming others predicted lower anxiety. Moreover, when commitment, which is also a factor of cognitive appraisal, was high, blaming others predicted lower well-being, whereas when commitment was low, positive refocusing predicted higher well-being. This study revealed that how people appraise a situation moderates the relationship between cognitive emotion regulation strategies and psychological health.