Identifying features of early care and education (ECE) settings that positively affect children's early learning and development is a critical challenge for the field. Most research related to this challenge has focused on structural features of ECE quality, such as teacher-child ratios and teacher credentials, and on process quality, which refers to aspects of teacher-child interactions. Another dimension of ECE settings that is receiving increased attention is teacher well-being and staff wellness. Research relevant to this topic has mainly focused on the degree to which ECE teachers show stress and other negative psychological states, such as worry, depression and emotional exhaustion, especially in response to workplace conditions. This brief examines research on ECE teachers' experience of various forms of stress and their associations with teaching practices, children's learning, and workplace conditions. The brief concludes with a set of policy recommendations informed by this research. For convenience, the term "stress" is used in summary statements and questions to reflect the broader range of negative states examined in the research. The following questions are addressed in this brief: 1. How prevalent is ECE teachers' experience of stress? 2. How does ECE teachers' work-related stress contribute to the quality of teaching practices and child outcomes? 3. What workplace factors contribute to ECE teacher stress? 4. What interventions and workplace supports promote teacher well-being? 5. What key policy recommendations are suggested by the research? (author abstract)