Impulsivity is a transdiagnostic risk factor for multiple disorders, including opioid use disorders (OUDs). However, scant work has examined if impulsivity facets distinguish individuals reporting nonmedical opioid use from those who use opioids as prescribed, particularly in important settings such as emergency departments (EDs). Further, no studies, to our knowledge, have examined the relations between impulsivity facets and motives for nonmedical prescription opioid use (NMPOU). Using data from EDs, this study examined if impulsivity facets (assessed via the [negative] urgency, premeditation, perseverance, sensation seeking, and positive urgency) related to nonmedical opioid use and if these facets related to OUD severity among individuals reporting past-year opioid use. Among patients reporting past 3-month NMPOU, the relation between motives for use and impulsivity was examined. Results indicated all facets (except lack of perseverance) distinguished patients reporting nonmedical opioid use from individuals abstaining from opioid use and those who used opioids as prescribed, with particularly large effect sizes for positive and negative urgency. Similarly, among patients reporting past 12-month opioid use, all facets (except lack of perseverance) significantly distinguished individuals who were OUD negative from those with severe OUD, with positive and negative urgency showing the strongest relations. Multiple motives were associated with certain UPPS-P facets, particularly positive urgency, negative urgency, and sensation-seeking. Results suggest that the relation between impulsivity and opioid use characteristics varies across facets of impulsivity, with emotion-based impulsivity being the most relevant. Implications for screening and interventions are discussed. (PsycInfo Database Record (c) 2024 APA, all rights reserved).