Background: For the purpose of understanding the Food and drug Administration’s (FDA’s) concerns regarding online promotion of prescription drugs advertised directly to consumers, this study examines notices of violations (NOVs) and warning letters issued by the FDA to pharmaceutical manufacturers.Methods: The FDA’s warning letters and NOVs, which were issued to pharmaceutical companies over a 10-year period (2005 to 2014) regarding online promotional activities, were content-analyzed.Results: Six violation categories were identified: risk information, efficacy information, indication information, product labeling, material information issues, and approval issues. The results reveal that approximately 95% of the alleged violations were found on branded drug websites, in online paid advertisements, and in online videos. Of the total 179 violations, the majority of the alleged violations were concerned with the lack of risk information and/or misrepresentation of efficacy information, suggesting that achieving a fair balance of benefit versus risk information is a major problem with regard to the direct-to-consumer advertising (DTCA) of prescription drugs. In addition, the character space limitations of online platforms, eg, sponsored links on search engines, pose challenges for pharmaceutical marketers with regard to adequately communicating important drug information, such as indication information, risk information, and product labeling.Conclusion: Presenting drug information in a fair and balanced manner remains a major problem. Industry guidance should consider addressing visibility and accessibility of information in the web environment to help pharmaceutical marketers meet the requirements for direct-to-consumer promotion and to protect consumers from misleading drug information. promotion via social media warrants further attention, as pharmaceutical manufacturers have already begun actively establishing a social media presence, and the FDA has thus begun to keep tabs on social media promotions of prescription drugs.