Reminiscence-based interventions involve the guided recall and interpretation of autobiographical memories to promote adaptive thinking. This study involved secondary analyses of a recent trial of a positively focused, group-based, three-session version of cognitive-reminiscence therapy (CRT) on perceptions of general relationship quality and interpersonally related psychological resources in young adults. A community sample ( N = 62, Mage = 24.6 ( SD = 3.1), 71% identified as cisgender women and 29% identified as cisgender men) of young adults were randomised into a CRT and wait-list condition. Participants completed assessments measuring perceived general relationship quality (relationship satisfaction, emotional intimacy, commitment, and trust) and perceptions of self and others within relationships (relationship self-esteem, relationship self-efficacy, relationship optimism and meaning in relationships). The CRT group, relative to the control group, scored significantly higher on perceived relationship quality ( d = .62), and higher on generalized relationship self-efficacy ( d = .70), relationship self-esteem ( d = .59), and relationship optimism ( d = .57) at the follow-up. Group differences for relationship meaning were not statistically significant (small to moderate). A brief, positive-focused intervention of guided recall of autobiographical memories led to more adaptive perceptions about self and others within the context of relationships in young adults. Replication studies with larger samples are needed, and outside of a pandemic lockdown context. Future research may expand CRT to target other relationship variables, assess the impacts of different doses, explore relationships in specific populations, and better understand the mechanisms for change.