Abstract Introduction Prostate cancer is the second-most prevalent cancer diagnosis worldwide among males. Although prostate cancer affects the physical, sexual, and mental health of patients, the impact of prostate cancer on partners has also been increasingly recognized. Hence, taking a dyadic approach is of relevance. Moreover, there is evidence of the utility of dyadic approaches to the study of relational stress that chronic diseases such as prostate cancer can bring to couples, even though knowledge is sparse about prostate cancer. Objectives This scoping review aimed to map existing dyadic studies on the psychosocial adaptation of couples to prostate cancer. Methods A systematic search of studies published from 2005 to November 2022 was conducted on electronic databases (PubMed, Cochrane Library, EBSCOHost, Scopus, and Web of Science) following PRISMA-ScR (Preferred Reporting Items for Systematic Reviews and Meta-analyses–Extension for Scoping Reviews). Results The review included 25 eligible studies from the initial 2514 articles retrieved. Overall, the results emphasized the interdependency between couple members and suggested how partners’ adaptation influences patients’ adaptation to prostate cancer and vice versa, regarding several psychosocial dimensions (eg, intimacy, quality of life). Conclusions This work can bring awareness to health care professionals to adopt a couples approach when managing prostate cancer whenever there is a partner, due to these interdependent influences. For researchers and future studies, this work can strengthen the relevance of dyadic approaches on how couples adapt to prostate cancer and explore which other dimensions influence these complex dynamics.