Lack of STEM-related self-efficacy has impeded the growth of women in STEM fields. Out of school (OST) robotics programs and other STEM-related OST programs provide secondary students with opportunities to work in groups, brainstorm, and formulate ideas that require communication and teamwork. The purpose of this quantitative, quasi-experimental study was to compare STEM-related self-efficacy scores among male and female students who participated in OST robotics programs or other OST STEM-related programming. Independent variables were type of OST STEM program and gender. The dependent variable was students' STEM-related self-efficacy as measured by the Coping Self-Efficacy Scale. Responses from 149 students in 4 southeastern U.S. metropolitan high schools were analyzed using a 2x2 factorial ANOVA. Findings indicated the relationship between STEM-related self-efficacy scores and type of OST programming was not moderated by gender. There was a significant main effect for program type. Students in the robotics OST programs demonstrated significantly higher STEM-related self-efficacy than did students in other STEM-related OST programs. Findings may be used to inform educators, community leaders, parents, and policymakers regarding the benefits of OST robotics programs, which may encourage women to obtain STEM-related degrees and pursue STEM careers. [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.]