Involvement of supportive others (SOs; defined as patient’s most important person) in substance treatment is widely accepted as a valuable addition to substance use treatment, but is not routinely implemented during inpatient detoxification for opioid use disorders. The current study explores the feasibility of a brief SO intervention for individuals detoxing from opioids. Data regarding ability to identify an SO, the nature of the SO relationship, and willingness to invite an SO to help with long-term abstinence were collected from 369 patients attending inpatient opioid detoxification. For those unwilling to participate in an SO intervention, possible barriers to participation were examined. Results indicated the majority (71.8%) of patients were willing to involve SOs, and that they believed that their SO was supportive of their treatment (88.1%). Those unwilling to invite an SO reported that their identified SO was a young child or that they wanted to make life changes independently. We conclude that SO involvement in substance use treatment at the time of opioid detoxification is feasible and could be engaged in future interventions.