To explore the use of mental health professional expertise in the legal system, legal professionals' sources of social science information, and the legal profession's perspectives on the appropriate roles of mental health professionals in the process, we solicited information from attorneys and judges on (a) the extent to which they actively seek the involvement of mental health professionals in child custody cases, (b) the factors that influence such involvement, and (c) the degree to which these attitudes and practices are influenced by social science data or theory. Among the most sinking features of these results was the report by the overwhelming majority of legal professionals that they did not consider either social science dala or mental health professionals' involvement or recommendations in child custody cases as critical to their practice of family law. Specifically, mental health participation was rarely solicited, and when it was. this decision rested primarily on the paradigmatic regularities of the legal system or practical needs of the case rather on a view that such involvement was central to the client's or child's mental health. The implications of these findings for collaboration between the mental health and legal disciplines in the area of family policy are discussed.As part of the growing commitment to preventing emotional dysfunction through social change (Albee, 1985). mental health professionals have sought to become participants in an ever-increasing range of efforts to shape legal policies and processes (e.g., Reppucci, Wcilhorn, Mulvey, & Monahan. ROBERT D. FELNER, PhD, is professor of psychology at the University oflllinois at Urbana-Champaign. His research interests are in primary prevention, life transitions, stress and coping in children and families, and child custody. He is an editor of Preventive Psychology. Theory. Research and Praam' (published 1983). RICHARD T. ROWLISON. MA, is a PhD student in the Clinical/ Community Psychology Program at the University of Illinois at Urbana-Champaign. His research interests arc in the areas of stress and coping and prevention programs for at-risk adolescents. STEPHANII S. FARBER, PhD, is in private clinical practice in New Haven, Connecticut. Her research interests focus on stress and coping in children and families. JUDITH PRIMAVERA, MA, is a PhD student at Yale University and a staff psychologist at Bridgeport Child Guidance Center, Bridgeport. Connecticut. THOMAS A BISHOP, Esq.. is a practicing attorney and former president of the Family Law Section of the Connecticut Bar Association. THE AUTHORS THANK the Family Law Section of the Connecticut Bar Association for their support for this project, and Lisa Terre for her assistance in data analysis and editing.