The purpose of this quantitative research study was to identify the critical thinking dispositions of undergraduate nursing students and nursing faculty in Southwestern Nigeria. Critical thinking dispositions are required for critical thinking skills. People who have critical thinking disposition exhibit seven traits: truth-seeking, open-mindedness, analyticity, systematicity, inquisitiveness, cognitive maturity, and critical thinking self confidence. While critical thinking is considered as an essential outcome for nursing education, evidence points to a deficiency of critical thinking skills in new nurses. Critical thinking research is lacking among nursing students in Nigeria. As a first step in addressing this problem, this study investigated the critical thinking dispositions of undergraduate nursing students and nursing faculty in Nigeria using the California Critical Thinking Disposition Inventory Scale (CCTDI). Using a convenience and purposive sampling, 509 undergraduate nursing students and 37 nursing faculty from 4 accredited nursing programs completed the CCTDI. Students demonstrated a weak positive overall disposition to critical thinking, with evidence of disposition not increasing significantly overtime. The subgroup means of the 7 trait sub-scores revealed a very homogeneous group with truth-seeking as lowest and inquisitiveness as highest. In contrast, nursing faculty demonstrated a strong positive overall inclination for critical thinking with lowest mean score on the truth-seeking subscale score and highest in inquisitiveness score. Together, the findings suggest that significant differences occurred in scores between the two groups. Implications for nursing education included integrating teaching and learning activities that can enhance truth-seeking, ensuring students' function as the creators of their own knowledge, and faculty becoming eager to learn how to train critical thinkers, exerting the mental effort needed to apply it. [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.]