Suicide can have a significant impact on the bereaved. Peer support groups for suicide bereavement have been shown to enhance the wellbeing of those attending. However, research is lacking on the mechanisms that underlie these benefits. Semi-structured interviews were conducted with 12 adults attending peer-facilitated support groups in Ireland and thematic analysis was used. The findings highlighted the enduring emotional impact including guilt and questioning, loss of identity, as well as wider impacts. Mechanisms of the groups included the opportunity to share experiences and feel validated, connection and belongingness and collective processing of grief. Groups were found to have a unique role alongside other informal and formal supports. This study highlights the important role of peer support groups in lessening this burden and adds to the literature through identifying potential mechanisms by which peer support groups contribute to improved wellbeing for the suicide-bereaved and practical steps to facilitate these mechanisms.