To examine the immediate effects of a comprehensive pain course on medical students' pre-existing perceptions and attitudes toward pain patients and opioid management. First-year medical students at a major academic medical center enrolled in a required pre-clerkship pain course in June 2020 and completed pre- and post-course online surveys with Likert-scale questions about their attitudes toward pain management and opioid-related issues. Additionally, the surveys included a free-text question where the students listed the first five words that came to mind when hearing the word "opioids". These words were categorized as "professional" or "lay" words and further as having "positive", "negative", or "neutral" connotations. Data analyses included descriptive statistics, as well as non-parametric and parametric tests. Fifty-four of the 119 students responded to pretest and posttest surveys and were included in paired analyses. There was a significant difference between the number of professional words used before (M=1.21, SD=0.97) and after the course (M=2.40 SD=1.33); t(52)=-6.39, P<0.001. Students also used more lay-positive words after the course (M=0.81, SD=0.63) than they used pre-course (M=0.23, SD=0.43); t(51)=-5.98, P<0.001. Students' post-course responses to several key Likert-scale questions showed significant shifts toward more positive attitudes about caring for patients with pain. For example, students acknowledged greater comfort in providing opioids for chronic pain (P<0.001) where appropriate, and enhanced interest in handling complex pain cases (P<0.001). Results showed that a comprehensive, multi-disciplinary pain course could greatly enhance first-year medical students' attitudes toward pain management, chronic pain patients, and the complex issues surrounding opioids.