Background: Technological developments in prosthesis design of upper limb devices are improving rapidly, and understandings of user's perceptions are important to reduce device abandonment and improve user satisfaction rates. Objectives: The purpose of this review was to establish what is known about adult user's perceptions of upper limb prostheses in terms of both cosmesis and function. Study Design: Systematic review. Methods: A search of the literature between 1990 and 2010 identified over 600 possible citations; these were reduced to 15 citations based on selection criteria. Results: The main themes arising from the review were user satisfaction ratings with current prostheses, priorities for future design and the social implications of wearing a prosthetic limb. While users of cosmetic prostheses were mostly satisfied with their prostheses, satisfaction rates vary considerably across studies, due to variability in demographics of users and an ambiguity over the definitions of cosmesis and function. Design priorities also varied, though overall there is a slight trend toward prioritising function over cosmesis. The qualitative studies noted the importance users placed on presenting a 'normal' appearance and 'not standing out'. Conclusions: The reviewed studies mostly examine functionality and cosmesis as separate constructs, and conclusions are limited due to the disparity of user groups studied. Recommendations are made for further work to explore understandings of these constructs in relation to upper limb prosthesis use.