As John Brekke has observed, social work does not use the word "science" to define itself, suggesting a need to articulate a science of social work. This article discusses the science of social work and its relationship to social work practice in the United States, arguing that a "rapprochement" between practice and science should be effected to their mutual benefit. It begins by unpacking both the definitions of social work and of science; considers epistemologies; and underlines the importance of theory in social work science and practice. The article concludes with ideas for identifying common ground and enhancing the practices of both scientists and practitioners in our field. These suggestions include acknowledging shared aims of improving care and services, fully embracing methodological pluralism, using theories and exploring domains within the field that are important to both practitioners and scientists, developing sustainable structures where scientists and practitioners can come together on an equal footing to learn from each other and to collaborate in practice-relevant research, and developing a knowledge broker service for practitioners.