Using ESG ratings from seven different data providers for a sample of S&P 500 firms between 2010 and 2017, we study the relation between ESG rating disagreement and stock returns. We find that stock returns are positively related to ESG rating disagreement, suggesting a risk premium for firms with higher ESG rating disagreement. Analysis shows that financial analysts who value the equity of firms should incorporate the effects of ESG rating disagreement and adjust their equity cost of capital estimates upwards.