Web 2.0 technologies, where users participate in content production, are increasingly used as informational and educational resources. Wikipedia is frequently cited by students in the healthcare professions. This study compared the accuracy and completeness of drug information in Wikipedia to Medscape Drug Reference, a traditionally-edited resource. Wikipedia answered fewer questions [40.0% vs. 82.5%] (p<0.001) and was less complete (p=0.00076) than Medscape. No gross errors were found in Wikipedia and its content has improved over time.