Men being treated for prostate cancer (PCa) commonly report a diminished sense of their masculinity, but it is not clear what contributes to that perception. Here we examined the literature to explore the characteristics most commonly used to describe diminished masculinity in PCa patients. Data were extracted from 42 peer-reviewed articles that referenced both PCa and terms associated with masculinity. We then ranked the terms by frequency and evaluated whether each reflected a biological feature (e.g., ability to achieve an erection) or a social norm (e.g., being a protector/breadwinner). We also recorded whether patient reports were self-generated or elicited through existing psychological assessment instruments chosen by researchers. We found notable differences between what patients perceived as a decline in their masculinity when spontaneously self-reported, and when elicited through preexisting measures. Patients most often reported changes in bodily function (e.g., reduced erectile function, libido, and physical strength), whereas their responses on formalized measures reflected social and psychological concepts (e.g., self-reliance and stoicism). Our results suggest that loss of masculinity experienced by PCa patients is largely experienced biologically as opposed to socially. Moving forward, interdisciplinary collaboration between those in biomedicine and psychosocial fields will be crucial for improving the quality of life of PCa patients. (PsycINFO Database Record (c) 2019 APA, all rights reserved)