The purpose of this study was to investigate the factors associated with teenagers' willingness to volunteer with elderly persons using an expanded model of the Theory of Planned Behavior (TPB). Participants consisted of 258 ninth-grade students at a large high school in the northern part of Israel. Participants completed a structured questionnaire consisting of 52 items, which examined their attitudes, subjective norms, perceived behavioral control, past behavior, personal identity, and perceived moral obligation. Their willingness to volunteer with elderly persons was assessed using six vignettes, varying in the severity of the elderly person's health and functional conditions described. Additionally, the students' sociodemographic variables were examined. Overall, students' willingness to volunteer with elderly persons was low; however, it increased when the elderly person in the vignette was described as relatively healthy. Statistically significant relationships were found between willingness to volunteer and personal identity, as well as between willingness to volunteer and attitudes toward volunteering with elderly persons. A statistically significant but moderate relationship was found between willingness to volunteer and subjective norms. Multiple regression analyses showed that attitudes, subjective norms, and personal identity were the main predictors of willingness to volunteer with elderly persons, explaining 58% of the variance. The expanded model of the Theory of Planned Behavior provided an appropriate framework for understanding the factors associated with teenagers' willingness to volunteer with elderly persons. Our findings stress the need to develop educational intervention programs regarding gerontologically-related subjects and to disseminate them among the population in general, and among youth in particular.