Objectives: The Adverse Events Reporting System (AERS) of the FDA is used to identify toxicities of drugs that are on the market. Nurse practitioners (NP) and physician assistants (PA), having an increasing role in the delivery of medical care, are also needed to participate in post-marketing pharmacovigilance. This study was performed to assess awareness and use of the AERS in voluntary reporting of drug toxicities by NPs and PAs. Methods: A cluster sample survey was issued at the Principles of Gastroenterology for the Nurse Practitioner and Physician Assistant course in August 2010. The survey assessed familiarity with the AERS, the number of adverse events seen and the frequency of reports sent to the AERS. NP and PA responses were compared using the two-tailed Fisher's exact. Results: Of the 92 respondents, 67 (72%) were NPs and 24 (26%) PAs. Of the 50 (54%) respondents that reported being familiar with the AERS system, 20 (40%) incorrectly identified the methods to report using the AERS. Overall reporting of adverse events was low, particularly in respondents seeing 5-12 adverse events per year. Conclusion: The study suggests that improved education regarding the importance of using AERS for pharmacovigilance is suggested for NPs and PAs. Due to the small size of the study, these data should be viewed as preliminary, pending a larger confirmatory study.