Although social identities and work-related commitment are important aspects of employee attachment, distinctions between and relations among the two have not been clearly articulated. In this conceptual piece, we propose that identity and commitment are distinguishable in terms of their essential meaning, foci of attachment, mindsets, volitionality, and behavioral implications. We further suggest that situated and deep structure social identities are differentially antecedent to exchange-based and value-based commitments, and that commitment mediates, at least partially, the effects of identities on motivation and work behavior. Finally, we consider the implications of multiple identities for employees in different kinds of collectives (nested and cross-cutting). Copyright © 2006 John Wiley & Sons, Ltd.