This paper empirically examines the effects of export product diversification on overall export quality in a panel data set of 115 countries from 1970 to 2010. It uses the data sets of the overall export quality and three export diversification measures of the International Monetary Fund: the extensive margin (variation in the number of new products exported), the intensive margin (variation in export values among existing exports), and the overall (Theil) index. It finds that export quality has only been increasing with a higher variation in export values among existing exports in low- and lower-middle-income countries. It also observes that export quality has been increasing with both a higher variation in export values among existing exports and new products exported in upper-middle- and high-income countries. The results are robust to the changing measures of controls in the benchmark model, the inclusion of many other controls; i.e. various measures of globalization, country size, factor endowments, macroeconomic stance, etc., and the exclusion of outliers.