A measure of entrepreneur success is important to identify current and future successful ventures, to further our understanding of the entrepreneurial process and to guide public policies to improve the success rate of start-ups. In this paper we propose an index of entrepreneur success that accommodates multiple inputs and outputs, that is predicated on inputs and that mitigates the impact of outliers. We relate the index to characteristics of the entrepreneur and the venture: age, experience, gender, race, competitive advantage, education, and birthplace. The data are from the Kauffman Firm Survey. The index is calculated for 2,863 firms in 2006.