Nationally, it was estimated that 11.4 million people misused opioids in 2017 with more than 47,000 opioid-related deaths. Although medication-assisted treatment (MAT) has been effective in enhancing treatment retention and decreasing frequency of opioid use, relapse rates for opioids and other substances remain high, emphasizing the importance of investigating novel interventions to augment MAT. One potential treatment approach is repetitive transcranial magnetic stimulation (rTMS)-a noninvasive, electrophysiological method of neuromodulation. Recently published studies of rTMS in individuals with alcohol, nicotine, and cocaine use disorder have suggested that this treatment shows promise in reducing cravings and substance use. The literature specific to rTMS and opioid use disorder (OUD) is limited to a single published study in heroin users, which showed that a single session of rTMS to the left dorsolateral prefrontal cortex (DLPFC) reduced cue-induced craving, with a further reduction following 5 consecutive days of rTMS. The following case report involved a 25-year-old Caucasian male diagnosed with OUD and cocaine use disorder. This subject continued to demonstrate ongoing substance use despite participating in comprehensive MAT with buprenorphine/naloxone in combination with psychosocial interventions. He was administered 7 separate sessions of rTMS targeting the left DLPFC. Substance-related cues were presented prior to, during, and following these rTMS administration sessions and the subject rated his substance cravings via a 100-point Visual Analog Scale. When compared with his cue-induced craving ratings, there was a mean reduction in craving for heroin and cocaine by ∼60% to 82% following the 7 administration sessions. Although this is a single case, further investigation of rTMS as an augmentation strategy for OUD and polysubstance use is warranted. (PsycINFO Database Record (c) 2020 APA, all rights reserved).