Introduction: Drug overdoses are the leading cause of accidental death in the United States. It is imperative to explore predictors of opioid overdose in order to facilitate targeted treatment and prevention efforts. The present study was conducted as an exploratory examination of the factors associated with having a past opioid overdose. Methods: Participants (N = 244) from substance treatment facilities, inpatient services following ER admittance, or involved within the drug court system and who reported opioid use in the past 6 months were recruited in this study. Measures of opioid use and history were used to determine characteristics associated with previous experience of a non-fatal opioid overdose. Results: Opioid users who were Caucasian and used a combination of prescription opioids and heroin were more likely to have experienced a prior overdose. Opioid user characteristics associated with greater odds of experiencing a prior overdose included: witnessing a friend overdose (OR 4.21), having chronic hepatitis C virus (HCV) infection (OR 2.44), reporting a higher frequency of buprenorphine treatment episodes (OR 1.55), and having a higher frequency of witnessing others overdose (OR 1.42). Greater frequency of methadone treatment episodes was related to decreased odds of experiencing an overdose (OR 0.67). Conclusion: Overall, this study demonstrated certain demographic and drug use factors associated with elevated risk for an overdose. Understanding the risk factors associated with drug overdose can lead to targeted naloxone training and distribution to prevent fatal overdoses.