As information provided in pharmaceutical marketing brochures has the potential to change doctors’prescribing behavior, ongoing efforts to increase awareness about drug promotion are crucial. However medical information in journal advertising has been criticized in several studies for being of poor quality. To find out the accuracy and ethical status of pharmaceutical marketing brochures about proton pump inhibitors prescribed in one university hospital in South Korea, six brochures were collected from pharmaceutical representatives visiting the family medicine out-patient department of that hospital between May 2010 to March 2011. We examined these brochures for the types of claims that were made, the amount and type of evidence provided, the authenticity of the quoted references, and whether or not the brochures satisfied the “World Health Organization (WHO) criteria 1988.” We also ascertained the source of funding for the original research cited in the brochures. Upon analysis, none of the promotional brochures fulfilled all of the WHO criteria. All brochures used emotionally loaded language and made exaggerated claims about the efficacy of the medicine in question. A total of 61 references were found in these brochures, 86.8% of which were journal articles. Of the journal articles cited in these brochures, 73.6% were SCI level, most were based on randomized controlled trials (RCT, 53.8%), and 41.5% were sponsored by pharmaceutical companies. Additionally, 17.1% of the claims made in these brochures were incorrect according to the published articles cited in the brochures, and 10.4% contained vague descriptions. We conclude that some of the information provided in pharmaceutical brochures for physicians is incorrect. Accordingly, we suggest that physicians need to be cautious about the reliability of information provided in drug advertisements and should follow the principles of evidencebased medicine in assessing the validity of information provided by pharmaceutical companies.