Functionality after upper limb replantation is a decisive factor when considering the success of the intervention. Therefore, its evaluation is fundamental. The aim of this article was to conduct a systematic review of upper limb functions after replantation or reimplantation, seeking to identify reported functional outcomes as well as the level and mechanism of injury. To achieve this objective, a literature search was conducted in PubMed, ScienceDirect, Cochrane and Web of Science. Studies from the last 10 years which included patients with upper limb replantation and reported their functional outcomes were included. Out of 523 articles, 12 studies (n = 607) were finally included. DASH and CISS were the most commonly used assessments to report functional outcomes. In conclusion, functional outcomes after replantation are assessed using widely varying scales; therefore, due to this methodological variability, it is difficult to compare functional success between studies and further studies on functionality are needed to provide new data.