Organizational citizenship behavior (OCB) is behavior in the workplace that is voluntary and beyond job task requirements. OCB is a subtle aspect of occupational safety and health programming that contributes to the overall quality of work life. An extensive body of literature, since 1983 and the establishment of the OCB concept, has shown that organizational level-factors predict OCB. Because OCB is extra-role behavior, it has been hypothesized that personality or dispositional factors should also be predictive of OCB. Recent research efforts, using the newly developed Prosocial Personality Battery, have found individual-level factors to predict OCB, accounting for variance beyond the organizational variables, although organizational factors remain the stronger predictor category. With the aging of employees and the population and with the need for workplaces to be prepared for emergencies and acts of terrorism, one important OCB is volunteerism for training in Automated External Defibrillators (AEDs) to deal with cardiac distress. This case-control survey of employees, trained and untrained in CPR/AED at a federal, health agency, used the electronic mail system with an embedded URL site to the worldwide web for data collection to assess individual and organizational factors associated with CPR/AED training. The questionnaire included the Prosocial Personality Batterys measures of self-reported altruism and personal distress to measure the dispositional factor of helpfulness. Univariate analyses identified job autonomy, job impact, personal distress (or ability to be effective and not lose control in crisis situations), education, volunteerism at work, tenure, job grade level, being in a professional licensure position, and being located at the agencys headquarters as significantly associated with CPR/AED training. The logistic regression models best predictors of CPR/AED training were (1) being in a professional licensure position, (2) being at headquarters, (3) having job self-efficacy, (4) having self-reported altruism, (5) personal distress (control and effectiveness), and (6) a negative interaction between selfefficacy and self-reported altruism. The model had a predictive concordance of 66.7 %. Without the interaction, predictive concordance dropped to 58.4%. The interaction demonstrated that volunteerism for CPR/AED training can be predicted by a high level of either altruism or job self-efficacy or by higher levels of job self-efficacy in the presence of low altruism or higher levels of altruism in the presence of low levels of job self-efficacy. However, at high levels of both, the prediction of CPR/AED training declines indicating, perhaps, a threshold or optimum level for the two factors together for predicting who will volunteer for CPR/AED training in this setting. The findings support the importance of both individual- and organizational-level factors in predicting the OCB of volunteerism.