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, three-session version of cognitive-reminiscence therapy (CRT) on generalised perceptions of relationship quality and interpersonally related psychological resources in young adults. A community sample (N = 62, Mage = 24.6 [SD = 3.1], 71% females) of young adults were randomised into a CRT and wait-list condition. Participants completed assessments measuring perceived 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 = 0.62), and higher on generalized relationship self-efficacy (d = 0.70), relationship self-esteem (d = 0.59), and relationship optimism (d = 0.57) at the follow-up. Group differences for relationship meaning were non-trivial (small to moderate), but not statistically significant. A brief, positive-focused, intervention of guided recall of autobiographical memories was generally effective in improving perceptions about self and others within the context of relationships in young adults. Replication studies with larger samples are needed. 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.