The task of developing vocational nursing students' critical thinking abilities is one of the greatest challenges facing nurse educators today. Licensed vocational nurses (LVNs) must be trained to think critically in order to provide safe patient care. Due to the expanded role and functions in the LVN's scope of practice, LVNs are making more complex decisions than ever before. The purpose of this study was to investigate concept mapping as a teaching strategy and the extent to which concept mapping impacts students' critical thinking skills and academic performance. A convenience sample of the entire enrollment of medical-surgical nursing course vocational nursing students (n = 33) participated in this quantitative descriptive study. Subjects completed two questionnaires: the California Critical Thinking Skills Test (Facione & Facione, 2000) to measure their critical thinking skills; and the California Critical Thinking Disposition Inventory (Facione & Facione, 1992) to measure their dispositions to think critically. Researcher created a demographic data form to collect gender, age, educational status, and academic level completed in the nursing program. Subjects' concept mapping grades were accessed for comparison with survey data. Data were analyzed using descriptive statistics, Pearson correlation, and t test. No difference in CCTST posttest scores are found between vocational nursing students' CCTST pretest scores. Overall, nursing students had high concept mapping scores, which are associated with increased critical thinking skills. Survey data supported a correlation between CCTDI posttest scores and concept mapping scores when compared to CCTDI pretest scores. Participants' dispositions toward critical thinking were positively correlated with the written achievement on concept maps as an increase in critical thinking skills. Findings from this study have implications for practice and vocational nursing education, and they support recommendations for future research. Critical thinking skills and dispositions to think critically can have a critical impact on whether an LVN is capable of practicing competently and safely in situations that involve clinical decision making in long-term care facilities, home-healthcare agencies, and other expanded roles of the licensed vocational nurse. [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.]