There is increasing interest in decision making in social work. Much of the attention has been on individual professional judgement rather than on group decisions processes. This paper outlines key theoretical approaches from diverse fields of knowledge for conceptualising professional group decision processes in child and family social work, as a framework for future research and more focused theoretical developments. The main theoretical approaches considered include (1) group consensus processes; (2) exchange and the use of information;(3) naturalistic studies emphasising group complexity; and (4) incremental improvement processes. The analysis highlights the possible impact of individual, organisational and contextual factors, as well as their complex interconnections, on group decision making. The paper provides a valuable resource for reflecting on group decision processes in child and family social work, and how they complement individual professional judgements and the interactive processes with children and families. Next steps for the development of practice, policy, and research to improve group decision making are discussed. Using theoretical models to underpin empirical research will enable greater connection to be made between studies, and hence further the knowledge base for social work in this field.