This paper examines the impact of earnings opacity on equity markets across 34 countries from 1985 to 1998. The authors construct a panel dataset to measure three dimensions of reported accounting earnings—earnings aggressiveness, loss avoidance, and earnings smoothing—and combine these measures to create an overall earnings opacity time-series for each country. They hypothesize that these dimensions are associated with uninformative or opaque earnings and explore whether this opacity affects the cost of equity and trading volume in the stock market. The results show that an increase in overall earnings opacity is linked to a significant increase in the cost of equity and a significant decrease in trading volume, both economically and statistically significant. However, the relationship between individual measures of earnings opacity and market outcomes is not always consistent. The paper also discusses the limitations of the measures used and the potential factors influencing earnings opacity.This paper examines the impact of earnings opacity on equity markets across 34 countries from 1985 to 1998. The authors construct a panel dataset to measure three dimensions of reported accounting earnings—earnings aggressiveness, loss avoidance, and earnings smoothing—and combine these measures to create an overall earnings opacity time-series for each country. They hypothesize that these dimensions are associated with uninformative or opaque earnings and explore whether this opacity affects the cost of equity and trading volume in the stock market. The results show that an increase in overall earnings opacity is linked to a significant increase in the cost of equity and a significant decrease in trading volume, both economically and statistically significant. However, the relationship between individual measures of earnings opacity and market outcomes is not always consistent. The paper also discusses the limitations of the measures used and the potential factors influencing earnings opacity.