This paper investigates the link between gender diversity in senior management and firm-level productivity. For this purpose, it constructs a novel cross-country dataset with information on firms’ senior management group and other firm characteristics, covering both publicly listed and unlisted firms in manufacturing and non-financial market services across nine OECD countries. The main result from the analysis is that productivity gains from increasing gender diversity in senior management are highest among firms with low initial diversity. Increasing the female share to the sample average of 20% in firms with initially lower shares would increase aggregate productivity by around 0.6%. This suggests that improving women’s access to senior management positions matters not only for equity but could yield significant productivity gains.