Proponents of IFRS argue that mandating a uniform set of accounting standards improves financial statement comparability that in turn attracts greater cross-border investment. We test this assertion by examining changes in foreign mutual fund investment in firms following mandatory IFRS adoption in the European Union in 2005. We measure improved comparability as a credible increase in uniformity, defined as a large increase in the number of industry peers using the same accounting standards in countries with credible implementation. Consistent with this assertion, we find that foreign mutual fund ownership increases when mandatory IFRS adoption leads to improved comparability. ► Foreign mutual fund ownership increases in the EU after mandatory adoption of IFRS. ► The increase in mutual fund ownership is larger when IFRS adoption improves comparability. ► Both implementation credibility and increased uniformity are important factors leading to improved comparability. ► The effects of improved comparability do not increase domestic mutual fund ownership. ► The effects of improved comparability on foreign fund ownership are primarily driven by foreign global funds, as opposed to foreign regional, country, and other funds.