The purpose of this study was to examine the relationships between career maturity and career decision-making self-efficacy and selected demographic characteristics. The study utilized three instruments for data collection: the Career Maturity Inventory (CMI-R), the Career Decision-Making Self-Efficacy Short-Form (CDSE-SF) and a demographic information survey, which was developed by the investigator. The population for this study was students attending a rural high school. All students in grades 9th-12th completed the Demographic Questionnaire, CMI, and the CDMSE-SF. Students selected for the study were chosen based on completion of the informed consent forms. This study was conducted as a longitudinal study over the course of three years. The population completed each of the instruments (CMI, CDSE-SF and Demographic Survey) in the fall of each academic year. Descriptive statistics were calculated for gender, ethnicity, extracurricular activities, athletic involvement, Advanced Placement courses and dual enrollment courses for 2013 and 2014. Correlation analysis and linear regression models were used to determine the relationship between career maturity and individual student demographic characteristics and the relationship between career decision-making self-efficacy and individual student demographics. Statistical analysis found students who did not take Advanced Placement (AP) courses had higher career maturity scores than those who took AP courses. Correspondingly, those students who took dual enrollment courses scored lower on the Career Maturity Inventory (CMI-R) than those who did not. Additionally, participation in extracurricular activities was found to be significant. Students who participated in zero to one activity had a higher CMI-R than those who participated in two or more extracurricular activities. Students who participated in two or three extracurricular activities and dual enrollment were found to have significantly higher CDMSE-SF means than others (p < 0.01). No other variables examined in this study were found to be significant. These findings suggested additional resources should be dedicated to career development by school administrators, counselors and teachers in order to enhance students' career maturity and career decision-making self-efficacy before the end of their secondary school experience. Further investigation should be conducted to further understand and enhance the process of career development in secondary students. [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://bibliotheek.ehb.be:2222/en-US/products/dissertations/individuals.shtml.]