Objective: We sought to identify optimal strategies for integrating HIV-and opioid use disorder-(OUD) screening and treatment in diverse settings. Design: Systematic review. Methods: We searched Ovid MEDLINE, PubMed, Embase, and PsycINFO and pre-identified websites. Studies were included if they were published in English on or after 2002 through May 2017, and evaluated interventions that integrated, at an organizational level, screening and/or treatment for HIV and OUD in any care setting in any country. Results: Twenty-nine articles met criteria for inclusion, including 23 unique studies: six took place in HIV care settings, 12 in opioid treatment settings, and five elsewhere. Eight involved screening strategies, 22 involved treatment strategies, and seven involved strategies that encompassed screening and treatment. Randomized controlled studies demonstrated low to moderate risk of bias and observational studies demonstrated fair to good quality. Studies in HIV care settings (n=6) identified HIV-and OUD-related clinical benefits with the use of buprenorphine/naloxone for OUD. No studies in HIV care settings focused on screening for OUD. Studies in opioid treatment settings (n=12) identified improving HIV screening uptake and clinical