Purpose <p>Social support interventions, particularly peer support from former family caregivers, offer unique assistance to caregivers of newly diagnosed patients. Since voluntary peer support is driven by personal choice, understanding the motivations for participating and how motivation evolves over time is essential. This study explores the motivations for becoming a peer support provider for family caregivers of patients with hematological malignancies and how motivation changes over time.</p> Methods <p>This qualitative study encompasses 18 semi-structured interviews with family caregivers providing peer support (<i>N</i> = 11) at two time points: (1) just after certification as peer supporters but prior to starting the peer support program and (2) at the 6-week mark of their 12-week peer support program. Interpretive phenomenological analysis was used to analyze the data.</p> Results <p>Motivation for participating in a voluntary peer-to-peer support program as a peer support provider center on four main themes: “<InternalRef RefID="Sec9">Driven by past experiences</InternalRef>”, “<InternalRef RefID="Sec10">Moral obligation is intrinsic to identity</InternalRef>”, “<InternalRef RefID="Sec11">Meaningful use of personal experiences</InternalRef>”, and “<InternalRef RefID="Sec12">Guiding new caregivers</InternalRef>”. Motivation was influenced during the support program, particularly by the presence or absence of feedback from family caregivers and by participation in network meetings with other peer support providers.</p> Conclusions <p>This study emphasizes the importance of networking meetings for family caregiver peer support providers, as they facilitate exchange of knowledge and insights and discussion of challenges and rewards and provide an ongoing support and motivation. It also highlights the untapped potential of volunteering to provide unique social support benefiting both the family caregiver recipient of support and the support provider.</p>