BackgroundResident physicians have been shown to possess negative attitudes toward individuals with substance use disorders (SUDs), even if the residents believe they have adequate knowledge and skills to care for these patients. Residents’ negative attitudes may have an adverse impact on patient engagement, treatment, and outcomes.Questions/PurposesThe goal of this study was to examine the impact of an online training module on residents’ attitudes toward people with SUDs. We hypothesized that residents who received the educational intervention would show improved attitudes toward people with alcohol and opioid use disorders.MethodsA web-based questionnaire, including demographic information and the Medical Condition Regard Scale (MCRS) about individuals with alcohol and opioid use disorders, was sent to internal medicine and psychiatry residents before and 6 months after they took an online training module on stigma toward individuals with SUDs.ResultsA total of 46 residents completed the initial questionnaire and 29 completed the follow-up questionnaire 6 months later. Attitudes toward individuals with SUDs, as reflected by an increase in MCRS scores, were improved 6 months after the online training module.ConclusionResidents’ attitudes toward individuals with SUDs improved after taking an online training module. This is encouraging, as studies have shown that attitudes toward individuals with SUDs tend to decline during residency training and negatively affect patient care. Larger studies are needed to determine if such online modules can improve attitudes of other groups of clinicians, result in sustained change over time, and improve patient outcomes.