A King’s Sierra Leone Partnership volunteer (senior mental health nurse or psychiatrist) provided regular supervision and mentoring. Weekly individual supervision of the local mental health nurse focused on clinical case review, service monitoring and continuous professional development. Monthly peer supervision including other mental health nurses in Freetown focused on clinical case review, sharing of resources (e.g. information about livelihood support programmes) and continuous professional development. The mhGAP guide was used in supervision to support case-based discussion learning and to reinforce its application within clinical practice.