This study aims to investigate whether qualified foreign institutional investors (QFIIs) improve companies' internal control quality to mitigate information asymmetry. By analysing a sample of 22,310 firm-year observations from Chinese listed companies between 2005 and 2017, we found that companies with QFIIs exhibit higher internal control quality and fewer internal control deficiencies. In particular, higher QFII ownership is associated with higher quality of internal control. Interestingly, QFIIs from high-governance-quality countries are more likely to improve the internal control system of their investee companies. Finally, the improvement in internal control quality attributed to QFIIs leads to better operating performance. Our results are robust to alternative measures of QFIIs, alternative proxies for internal control quality, and various controls for endogeneity issues.