Medication errors are one of the most common types of medical errors involving a substantial number of individuals and accounting for a sizable increase in healthcare costs (Institute of Medicine, 2000, To Err Is Human: Building a Safer Health System, National Academies, Washington, DC). These errors are also potentially injurious or fatal (2008, “National Study on the Frequency, Types, Causes and Consequences of Voluntarily Reported Emergency Department Medication Errors,” J. Emerg. Med., in press). Currently, particularly in time critical tasks, such as during the treatment of a cardiac arrest, drugs may not be properly documented. This leads to an increased likelihood of subsequent medication errors with the patient. In order to efficiently and accurately record the time a drug is delivered, a device is needed that (1) records information with little or no intervention by the healthcare professional, so that they are free to focus on their primary task (of particular relevance in time critical tasks), (2) provides a precise time mark, and (3) is reliable for proper documentation. The prototype device proposed here for marking the time of drug delivery involves the use of radio frequency identification (RFID) technology. Each drug dose (i.e., the typically used preloaded syringes or packages) is labeled by a RFID tag mounted on it in terms of the type of drug and its dosage. Both the drug and the tag are enclosed in a radio frequency shielded sleeve to prevent the tag from being read prematurely by the time marking system. The time marking system itself consists of a RFID reader and a software or hardware based internal clock. When a drug is administered to a patient, the sleeve is opened, the drug is removed, and the RFID tag transmits encoded information to the reader, which then records the time of an internal clock. This setup results in the proposed time marking system providing a hands-free documentation of the time at which a specific drug is administered. The device requires little or no training on its use, is fast and efficient, can be easily integrated with current medical technology, and can be adapted to the various constraints of a healthcare setting. Requiring no time from healthcare professionals to mark the time of drug administration, the proposed time marking system will help alleviate error in documenting drug delivery.