Police notifications of incidents of domestic violence to child protection services constitute an acknowledgement of the harm that domestic violence inflicts on children. However, these notifications represent a substantial demand on child welfare services and the outcomes for children and victims of domestic violence have been questioned. This paper presents findings from the first UK study to examine these notifications in depth and examines the interface between the police and child protection services in responding to domestic violence incidents. The research reports on police interventions in 251 incidents of domestic violence involving children; the communication of information to child protection services and the subsequent filtering and service response. Social workers found that notifications conveyed little information on children's experiences of domestic violence. Forty per cent of families notified had had no previous contact with child protection services in that area, but those cases most likely to receive social work assessment or intervention were those where the case was already open. Notifications triggered a new social work intervention in only 5% of cases. The study also identified a range of innovative approaches for improving the co-ordination of police and child protective services in relation to children's exposure to domestic violence. Arrangements that maximized opportunities for police and social workers to share agency information appeared to offer the best option for achieving informed decisions about the appropriate level of service response to children and families experiencing domestic violence.