This paper investigates the impact of overseas subsidiaries' R&D activities on the productivity growth of parent firms using firm-level panel data for Japanese multinational enterprises. We distinguish between overseas R&D for the utilization and acquisition of foreign advanced knowledge, or innovative R&D, and overseas R&D for the adaptation of technologies and products to local conditions, or adaptive R&D. Our major finding is that overseas innovative R&D helps to raise the productivity growth of the parent firm, while overseas adaptive R&D has no such effect. In addition, we examine whether overseas innovative R&D has an indirect effect on home productivity growth by improving the rate of return on home R&D. However, we find no evidence of such an indirect effect, suggesting that overseas innovative R&D does not engender any knowledge transfers from overseas to home R&D units.