This article is concerned with the role of intangible resources in business strategy. In particular it is concerned with identifying the intangible sources of sustainable competitive advantage. Sustainable competitive advantage results from the possession of relevant capability differentials. Regulatory and positional capabilities are concerned with intangible assets; functional and cultural capabilities are concerned with competencies. A framework linking intangible resources to capabilities has been devised and is used as the basis of a new technique for identifying the relative contribution which the different intangible resources make to competitive advantage. The results of the use of this technique in six case studies are reported.