The voluminous strategy research on the determinants of corporate scope is often premised on a well-established property rights regime, which contrasts with the weak property rights protection that still characterizes most countries today. We address this gap by applying property rights theory to theorize and empirically examine how the strengthening of the property rights regime affects corporate scope. Our analysis exploits the enactment of a property law that enhanced the formal protection of private properties in China as a quasi-experiment. We show that with a strengthened property rights regime, the horizontal relatedness among private firms’ businesses increases, but their vertical relatedness decreases, compared with state-owned firms. Further, these effects are less prominent for politically connected firms that are afforded informal protection of property rights. Our findings shed new light on the property rights regime as a critical determinant of firms’ horizontal and vertical scope.