Our research examined the role of challenge and hindrance stressors, as well as the interactive effects of these stressors with positive and negative affect, in predicting work engagement and exhaustion using experience sampling methodology. In Study 1, university staff completed measures of challenge and hindrance stressors, positive and negative affect, work engagement, and exhaustion before the end of the workday over 5 working days. Results from multilevel regression indicated that challenge stressors were positively related to work engagement but not exhaustion, while hindrance stressors were unrelated to both work engagement and exhaustion. Additionally, positive affect moderated the association between challenge stressors and both work engagement and exhaustion. We partially replicated and extended these findings in our second sample of Amazon's Mechanical Turk workers, who completed measures of affect in the mornings before starting work and stressors, work engagement, and exhaustion in the evenings before leaving work, over a period of 10 working days. Results suggested that challenge stressors were positively related to work engagement and exhaustion, while hindrance stressors were positively related to exhaustion and negatively related to work engagement. Similar to our results in Study 1, we found that positive affect interacted with challenge stressors in predicting each work outcome. Furthermore, positive affect moderated the hindrance stressor-work outcomes relationship. Lastly, negative affect moderated the association between challenge stressors and exhaustion. The findings of this study can be used to design interventions that enhance employee motivation and engagement in the presence of challenge and hindrance stressors.