Supported by Bandura's social cognitive theory, our study examined personal factors and environmental factors that impact adults' ability to assist youth in developing leadership. We introduce youth leadership development self-efficacy (YLD-SE) as a new construct for use in leadership research. A 7-item scale to measure YLD-SE was developed and its psychometric properties were established through exploratory factor analysis. The study sought to investigate the YLD-SE of agricultural education teachers, determine the relationship that YLD-SE has with selected variables, and determine the predictors of YLD-SE. Participants were agricultural education teachers (N = 177) in [Midwestern state] who taught during the 2005-2006 school year. Results showed that teachers perceive they have a high level of YLD-SE, and hierarchical regression analysis revealed that transformational and laissez-faire leadership style were significant predictors of YLD-SE. The full model explained 25% of the variance in YLD-SE.