Background: More than 263,000 individuals died due to prescription opioid misuse between 1999 and 2020. Between 2013 and 2015 alone, pharmaceutical companies spent over $39 million to market opioids to over 67,000 prescribers. However, there is still limited information about differences in provider responses to promotions for medications. In this study we investigated and evaluated strategies used by opioid manufacturers to encourage overprescribing, specifically focusing on oncology. Methods: We conducted a retrospective review of opioid industry documents released in litigation between 1999 and 2021. We began with a preliminary search for business plans in a subset of collections that identified key terms and phrases. These search terms were then used to narrow the investigation, which ultimately focused on Insys Therapeutics, and how they targeted oncology providers as well as patients with cancer pain. Results: We found that, overall, Insys sought to market to institutions with fewer resources, to less experienced and high-volume providers, and directly to cancer patients, with the goal of encouraging increased opioid prescribing and use. Conclusions: Our research revealed gaps in provider training that may make some providers more susceptible to pharmaceutical marketing. Developing and promoting continuing education courses for providers that are free from conflicts of interest, particularly at smaller institutions, may be one step towards reducing opioid overprescribing and its associated harms.