This work explores the understanding and experiences of Cafcass practitioner’s engagement in high conflict disputes involving implacable hostility. Design/methodology/approach: Cafcass practitioners are responsible for the preparation of welfare reports to the family court under section 7 of the Children Act 1989 (Cafcass, 2014). These reports are designed to assess what is in the best interests of the child when parents are in dispute over the child’s contact arrangements under private law proceedings (Cafcass, 2014). Semi-structured interviews were conducted with 7 participants (Cafcass practitioners). Data were analysed using thematic analysis. Findings: The study finds that practitioners require more assistance in identifying implacable hostility earlier, and also require help in how best to weigh up the ‘balance of harm’ to the child in individual cases. The study also discusses recent developments in the nature of high conflict cases, including the role of social media in accentuating hostility.