A community‐based cross‐sectional study was conducted to explore the relationship between parental personality disorder and child maltreatment. This article reports on the findings of a study focusing on a subsample of 46 maltreating mothers who had all been referred for psychological assessment in the context of care proceedings. Of the 46 mothers, 13 met the full diagnostic criteria for borderline personality disorder (BPD). Of the remaining 33 mothers, 18 presented with strong features of BPD but did not meet the full criteria and 18 presented with no significant features of BPD. Results indicated that maltreating mothers with diagnosed BPD were more likely than those with BPD features and those with no significant features to have engaged in the perpetration of physical and multiple (physical abuse and neglect) types of child maltreatment. No association was found between BPD and child neglect alone. Compared to the two other groups, mothers with BPD were identified as a particularly traumatised subgroup. The tentative conclusion that may be drawn from these findings is that maltreating mothers with BPD may represent a particularly high‐risk subgroup. The results are discussed with reference to existing empirical research. Implications for clinical practice and future research are then considered. Copyright © 2014 John Wiley & Sons, Ltd. ‘46 maltreating mothers… referred for psychological assessment in the context of care proceedings’ ‘Maltreating mothers with BPD may represent a particularly high‐risk subgroup’ Key Practitioner Messages BPD is a risk factor for interpersonal violence. Results of this study suggest that BPD may also be a risk factor for the perpetration of physical child abuse and multiple maltreatment (physical abuse and neglect) amongst mothers involved in care proceedings. Maltreating mothers with BPD may represent a particularly high‐risk subgroup.