In 2017, the Evidence-Based Practice Group conducted reviews on naltrexone as treatment for complex regional pain syndrome (CRPS) (June 2017), and neuropathic pain (September 2017). The 2017 systematic review was updated in 2019 with the aim of determinining whether there was new evidence to support the efficacy and/or effectiveness of naltrexone as treatment for neuropathic pain or complex regional pain syndrome (CRPS). The 2019 review update was subsequently updated in 2020. In this review, we update the 2020 systematic review with the same objective.