One of the goals of Child Protective Services (CPS) is to prevent maltreatment deaths. We analysed deaths of children younger than five years of age with an already open CPS case at the time of death for characteristics that might be associated with increased risk of fatality with child maltreatment. We used 2513 cases in the National Center for Fatality Review and Prevention – Case Review System during the years 2004–2016 for children ages 0–4 years who died with an already open CPS case. Among these, we compared 1370 children who died from causes determined to be ‘caused or contributed to’ by abuse or neglect to 1143 children who died from other causes. Those who died from maltreatment were older, experienced prior maltreatment, lived in an overcrowded residence, and had a caregiver with history of substance abuse, interpersonal violence, criminal delinquency and their own maltreatment. These risk factors and others may be associated with a higher likelihood of dying with abuse or neglect for children who already have an open CPS case.Key Practitioner Messages Compared with children dying from other causes, children with an already open CPS case at the time they died as a result of maltreatment were more likely to be older, male and living in a parental home with overcrowding. Caregivers were more likely to be male, or had a history of substance abuse, delinquency or prior maltreatment, both as a victim or perpetrator. When cases are opened with CPS, caseworkers should consider these potential risk factors and whether additional services can be put in place to reduce future maltreatment fatality. While additional research is needed, we speculate that other services, such as coordinated paediatric care, universal reporting, child fatality review teams, citizen review panels and public education campaigns, can offer additional ways to decrease future maltreatment deaths.