The number of Americans seeking treatment for opioid use disorder (OUD) continues to increase. However, there are important nutritional implications of having OUD that often get overlooked by drug treatment providers. OUDs can cause metabolic changes, constipation, and weight loss, or lead to a lifestyle that results in inadequate food intake and unhealthy eating patterns. Nutritional factors associated with OUD can also hinder treatment outcomes and recovery. Addiction providers tend to give little attention to the nutritional implications of OUD, and this knowledge is rarely incorporated into treatment plans. The goal of this article, therefore, is to summarize the existing literature on the connection between OUD and nutrition to help guide treatment programs. This article (a) describes the nutritional consequences associated with misusing opioids, (b) discusses the role that nutrition can play in OUD treatment and recovery, (c) summarizes the nutritional implications of medication treatment for OUD, and (d) recommends nutritional interventions that might aid in the treatment of OUD. This article directly fills a gap in the OUD literature and has the potential to serve as a guide for drug treatment providers to make more informed nutritional recommendations to their clients. Treatment programs may wish to consider the issues raised in this paper before launching nutritional programs at their facility. (PsycInfo Database Record (c) 2020 APA, all rights reserved).