Hardiness is a personality construct which is assumed to protect the individual from stress-induced illness. Although widely accepted, hardiness has shown only modest relations with the development of illness. Examining the components of hardiness indicates apparent consistency with organizational citizenship behaviors such as obedience, participation, and loyalty. This study investigated the potential relations between hardiness and organizational citizenship behavior, using Kobasa's Personal Views Survey, and Van Dyne, Graham, and Diensch's citizenship measure. Subjects were 129 unionized employees whose mean age was 37 yr.; 58% were men. Correlations and regressions indicated that scores for total hardiness and its components of commitment and control were linked to citizenship behaviors. Differential relationhips were identified between hardiness and citizenship behavior for individuals with high versus low scores on hardy personality. Hardiness appears to have a positive association with organizational effectiveness through its link to citizenship behavior and consequently may have more implications for organizational behavior than for health.