Resource-based theory (RBT) has emerged as a key perspective guiding inquiry into the determinants of organizational performance. Since the early 1990s, numerous studies have examined RBT's assertion that the extent to which organizations possess strategic resources is positively related to performance. Although many studies appear to support this assertion, there is no consensus regarding how strongly strategic resources relate to performance. To help resolve this issue, we meta-analyze 125 studies of RBT that collectively encompass over 29,000 organizations. Our conservative estimate is that the effect size of the strategic resources–performance relationship is r̄c = 0.22. Moderator tests suggest that the resources-performance link is stronger (1) when resources meet the criteria laid out in RBT and (2) for those performance measures that are not affected by potential value appropriation. When resources meet RBT's criteria and when performance measures are not affected by potential appropriation, the strength of the relationship grows to r̄c = 0.29. This suggests that the identification, development, and distribution of value from strategic resources should be a primary consideration for scholars, managers, and shareholders. Copyright © 2008 John Wiley & Sons, Ltd.