The purpose of this study was to explore the effects of using simulation and didactic instruction on critical thinking and clinical judgment with student nurses enrolled in a fall semester medical-surgical class. Specifically, it was of interest to compare the performance of these fall semester nursing students with the performance of nursing students enrolled in a spring semester class who received only didactic instruction. The study consisted of 18 participants who were nursing students enrolled in the senior level Adult Medical-Surgical III, the third medical-surgical class in the curriculum. There were two non-randomized groups. The experimental group received the intervention, which was a combination of three-hour lecture classes paired with one-hour simulation activity planned around the lecture topic. The integrated method went on throughout the semester. The control group had three hours of lecture alone. Both groups took the California Critical Thinking Skills pretest and posttest. Clinical judgment was also evaluated. All nursing students in groups of three led a simulation scenario. The four scenarios consisted of material covered throughout the semester: Myocardial Infarction, Respiratory Distress, Trauma, and Diabetic Ketoacidosis. The nursing students selected their scenario blindly and were to take the charge nurse position in the care of the patient. The scenarios were performed in the simulation lab with "Sim Man," a high-fidelity human simulator. The scenarios were videotaped using a three-view video feed, which allows for multiple views. The nursing students were evaluated using a modified Lasater rubric that had been individualized to each scenario. The results of the study indicated no statistically significant changes between either group. Recommendations for nurse educators include utilizing opportunities in the classroom, simulation lab, or in the clinical area for nursing students to practice complex decision making in a safe, simulated setting using the nursing process. Additionally, nursing students should be encouraged to take advantage of internships. [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/en-US/products/dissertations/individuals.shtml.]