This article discusses the promise and problems associated with integrating research on child temperament and research on childhood psychopathology. Unfortunately, these 2 extensive and influential areas of psychological research with children have largely been conducted independently of each other. This article provides a summary of the disciplinary, conceptual, and methodological issues that have hampered an integration of these 2 important bodies of research. It also highlights the great promise that such an integration could have for advancing causal theories of childhood disorders and for eventually improving the treatment provided to children with serious emotional and behavioral disturbances.