Gompers et al. [Gompers, P., Ishii, J., Metrick, A., 2003. Corporate governance and equity prices. Quarterly Journal of Economics 118, 107–155] created G-Index, a summary measure of corporate governance based on 24 firm-specific provisions, and showed that more democratic firms are more valuable. Bebchuk et al. [Bebchuk, L., Cohen, A., Ferrell, A., 2005. What matters in corporate governance? Working Paper, Harvard Law School] created an entrenchment index based on six provisions underlying G-Index, and found it to fully drive the Gompers et al. (2003) valuation results. Both G-Index and the entrenchment index are based on IRRC data that is comprised of anti-takeover measures, focusing on external governance [Cremers, K.J.M., Nair, V.B., 2005. Governance mechanisms and equity prices. Journal of Finance 60, 2859–2894]. We create Gov-Score, a summary governance measure based on 51 firm-specific provisions representing both internal and external governance, and we show that a parsimonious index based on seven provisions underlying Gov-Score fully drives the relation between Gov-Score and firm value. Our results support the Bebchuk et al. (2005) findings that only a small subset of provisions marketed by corporate governance data providers are related to firm valuation, and the Cremers and Nair (2005) evidence that both internal and external governance are linked to firm value. The 51 governance provisions we consider include five that are relevant to accounting and public policy: stock option expensing, and four that are audit-related. We find none of these five measures to be related to firm valuation. We document that only one of the seven governance provisions important for firm valuation was mandated by either the Sarbanes–Oxley Act of 2002 or the three major US stock exchanges. We provide researchers with an alternative measure of governance to G-Index with three distinct advantages: (1) broader in scope of governance, (2) covers more firms, and (3) more dynamic, reflecting recent changes in the corporate governance environment.