This study explores the effect of insider trading restrictions on corporate share repurchase decisions using a large sample of firms across 21 countries. We find that firms in countries with stricter insider trading restrictions exhibit a higher propensity to undertake share repurchases and buy back higher amounts of shares. Our identification analysis shows that the effect of insider trading restrictions on repurchases is more pronounced in firms with growing future operating performance, and in countries with a greater proportion of equity-based executive compensation and stronger private law enforcement power. Furthermore, we find that ownership concentrated firms are less likely to repurchase and such propensity is mitigated when countries establish stronger insider trading restrictions, implying that the restrictions of insider trading alleviate corporate insiders’ incentive to hold back private information and induce them to turn to open market repurchases. Our additional test demonstrates that share repurchases contribute to a larger firm value in countries with stronger insider trading law. This study sheds light on the substitute effect of insider trading and corporate share repurchase on signaling firm value.