The goal of the current study is to examine the relationship between corporate governance ratings and company value, for all the companies included in the S&P 100 Index, with the exception of companies involved in the financial sector, using data for 2013. The value of the company is quantified using the Tobin’s Q ratio and the Enterprise Value, adjusted according to each activity sector. The corporate governance practices are reflected using the ISS Governance QuickScore 2.0 overall rating, provided by the Institutional Shareholder Services Inc. (ISS), as well as ratings for the board structure, compensation, shareholder rights, and audit. By estimating cross-section regression equations, we revealed the lack of a statistically significant relationship between the corporate governance ratings and company value. Therefore, when making investment decisions, these corporate governance ratings should be taken into consideration with certain reservations.