Many studies have shown that pharmaceutical marketing affects prescribing choices. Studies that have assessed the effects of educational interventions on perceptions of pharmaceutical promotion have found mixed results. This study assesses the short-term effects of an educational intervention about marketing tactics on the attitudes and fund of knowledge of residents, medical students, and attending physicians. A 1-hour slide show that covered detailing, prescription tracking, drug samples, medical meetings, and journals was developed by PharmedOut and presented at a total of 14 grand rounds and seminars at departments of family medicine, internal medicine, pediatrics, psychiatry, cardiology, and neurology. Pre- and posttests included attitudinal and fact questions addressing the influence of drug reps, gifts, pharmaceutical advertising and drug samples on prescribing behavior. The posttest asked whether attendees intended to change their prescribing behavior. The Mann-Whitney U test was used for Likert-scale questions and the Fisher exact test was used to compare the number of pre- and posttest correct answers for the multiple choice and true/false questions. Three hundred seventy-three participants completed pre- and posttests. Significant attitudinal shifts were seen overall, particularly in questions addressing influence of salespeople on physicians in general and on the respondent individually. Some participants commented that they intended to stop seeing drug reps or stop attending industry-funded meals. A new educational presentation can substantially shift attitudes toward perceived susceptibility to pharmaceutical marketing activities. Further research is needed to see if attitude change persists.