Abstract We examine the effect of coverage by ESG rating agencies on firm ESG performance. We find that, when firm ESG coverage intensifies, its toxic emissions decline and its outstanding ESG ratings improve. ESG coverage is associated with fewer government enforcement actions for environmental and social violations and higher institutional ownership, especially by institutions with revealed preferences for high-ESG stocks. We also show that more covered firms disclose more ESG information in their annual reports. The effect of coverage is enduring and pronounced across both more and less competitive industries. Our results suggest that ESG rating agencies increase the amount of ESG information in the market. The source of this information could be attributed to the agencies’ expertise in evaluating ESG performance.