Social work provision outside conventional working hours is an under-researched aspect of practice. This study identifies and explores the nature of out of hours or emergency duty team (EDT) practice, beginning from the proposition that it is qualitatively different from daytime social work provision. The principal perspectives and voices which inform this study are those out of hours social work practitioners and practitioner-managers themselves. The methodology employed involved three distinct elements. These were: semi-structured interviews with a sample of practitioners working in a range of locales throughout England, participant observation of out of hours practice and the inspection and analysis of documentary records. Data analysis combined thematic and narrative approaches. Following a review of related literature and an introduction to the methodology, routes to out of hours work are considered. Specific features of the out of hours practice context are outlined, followed by a focus on the processes of practice and understandings derived from an analysis of records of practice. Practitioner perspectives are then presented and explored in relation to a wide range of issues, allowing new insights to be developed in a variety of areas. These include the interplay between the worlds of work and non-work, the character of relations between out of hours and mainstream social work services and other agencies, how practice is documented and accounted for, the particular significance of narrative in out of hours practice, and the importance of discretion and autonomy in connection with professional social work. Morale as a concept is a previously neglected topic which is also addressed Together these insights allow the nature of our of hours social work to be delineated. The final chapter combines individuals' thoughts about their occupational futures with wider perceptions of the future for out of hours social work services.