The resource-based view of the firm, with its focus on firm-specific 'capabilities', has attracted considerable attention in recent work by management scholars, but has not sparked much empirical analysis. This paper relies on the resource-based view to examine partner choice in interfirm collaborations, emphasizing the role of partners' technological capabilities. Patent citation data are used to measure 'technological overlap' between firms before and after alliance formation. Our results provide support for the resource-based view of the firm. Partner selection can be predicted by measures of technological overlap and, once formed, alliances appear to affect firms' technological portfolios in ways predicted by the resource-based view. (C) 1998 Elsevier Science B.V. All rights reserved.