The present study tested the theoretically inferred but not yet empirically tested association between dispositional optimism–pessimism and attachment security among 423 Finnish women and men. A second-order latent variable representing a generalized representation of attachment insecurity in close relationships that included two latent constructs, the one representing romantic adult attachment dimensions and the other representing recollections of attachment-related childhood family relationship, was associated with greater pessimism; the adult attachment dimension of high anxiety had unique and additional explanatory power, not accounted for by the generalized representation of attachment-related insecurity. The model explained 48% of the variance in pessimism. The results clearly emphasize that additional studies are needed to clarify the role of interpersonal processes in dispositional optimism–pessimism. Copyright © 2004 John Wiley & Sons, Ltd.