Fatal overdoses involving pharmaceutical opioids have increased dramatically over the past decade, surpassing those related to heroin, and are the leading cause of drug overdose in much of the U.S. In Seattle- King County, 75% of drug overdoses involved pharmaceutical opioids and/or heroin in 2009. Opioid overdoses, heroin and pharmaceutical, are preventable and reversible. Recent research suggests that opioid users at risk for overdose have higher rates of HIV risk behaviors. The emergent group of heroin users who were initially dependent on pharmaceutical opioids (39% of heroin users according to a 2011 Seattle survey) has significantly lower HIV risk perceptions and HIV testing rates. Research indicates that drug users and their partners can be successfully trained to recognize and reverse overdoses with naloxone. Despite active heroin overdose prevention and intervention programs with naloxone (OOPIN) in 15 states with thousands of overdose reversals and no serious adverse events, rigorous studies of these programs on rates of subsequent heroin overdoses have not been conducted. No OOPIN programs or studies have yet been implemented for pharmaceutical opioid users at elevated risk for overdose. The Emergency Department (ED) setting holds great promise for identifying and recruiting those at elevated risk of heroin and pharmaceutical opioid overdose: 1) the ED study site for this proposal provides most services to those needing care for acute opioid related medical problems in Seattle, and 2) patients need for urgent medical attention may heighten their concern about potential harms from opioids. Unique to this setting is the potential to identify high risk pharmaceutical opioid users. ED interventions using brief behavior change counseling (BBCC) have been shown to significantly improve health behaviors such as alcohol use and injury, to increase entry into drug treatment as well as to reduce costs. Evidence is promising, but limited, regarding the impact of BBCC on opioid related risk behaviors. This prospective, randomized ED trial will study the effectiveness of an intervention that combines OOPIN with BBCC for both heroin users (n=500) and pharmaceutical opioid users at elevated risk for overdose (n=500). The primary outcome is subsequent opioid overdoses, ascertained by follow up interviews conducted at 3, 6 and 12 months as well as via administrative records for up to 24 months (i.e. medical records, ambulance responses, and death certificates). Hypotheses to be investigated include that the intervention recipients will have: 1) lower rates of opioid overdose, 2) reduced drug use and overdose risk behaviors, 3) more appropriate health care utilization, and 4) lower total health care costs. We will also determine the prevalence of HIV risk behaviors and the impact of the intervention on these behaviors. Excellent data systems and several features of clinical practice and policy make Seattle the ideal place to conduct this research. The study team is uniquely qualified to conduct this study and will be adapting interventions with which they have years of research and clinical experience.