While the issue of teacher stress is widely recognized, little is currently known about childcare teachers’ stress, its impact on teaching, and the relationship with professional activities. This study utilizes ecological momentary assessment (EMA) techniques with 50 early care teachers to examine the relationship between childcare teachers’ reported stress, positive teaching practices, and participation in evening professional activities through the theoretical lens of Conservation of Resources (CoR). These results suggest that childcare teachers report higher levels of overall stress (stress intensity and stress exhaustion) when engaged in more evening professional activities and perform fewer positive classroom behaviors. When childcare teachers perceive greater stress intensity for current classroom activities, they also report higher levels of stress exhaustion. (author abstract)