Medication errors are a leading cause of injury and death in health care, and nurses are the last line of defense for patient safety. Nursing educators must develop curriculum to effectively teach nursing students to prevent medication errors and protect the public. The purpose of this quantitative, quasi-experimental study was to determine if high-fidelity simulation was an effective learning strategy to train associate degree nursing (ADN) students to reduce medication errors. Kolb's Experiential learning theory provided the framework of the study. ADN students applied past knowledge to an adult medical-surgical simulation and made errors when administering medication. The students participated in self-reflection during a debriefing session. The students applied new knowledge in a second simulation and made fewer errors. This study determined that the ADN students made fewer medication errors after participating in high-fidelity simulation (p<0.05). This is the first study that addresses using simulation as a learning strategy to decrease medication errors in ADN students, filling a gap in the research. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com.bibliotheek.ehb.be/en-US/products/dissertations/individuals.shtml.]