This paper describes the development of an instrument for assessing enterprise capability in schools. The approach to assessing enterprise capability builds on previous work by including three dimensions: self-efficacy, aspirations and knowledge and awareness. We find significant but weak associations between these three constructs suggesting that that, whilst they can be considered as providing a coherent description of enterprise capability they can also be regarded as distinct dimensions. The instrument also distinguishes between aspiration towards not-for-profit and for-profit enterprise and also between self-efficacy towards two broad enterprise capabilities: (i) project planning and (ii) working with people and information and two specific, market related capabilities: (iii) market risk and (iv) price and profit. We found only modest associations between students' sense of enterpriser self-efficacy and their enterprise knowledge and awareness.