This paper undertakes a comparative study of global production sharing by automakers in Japan, the United States and Western Europe, with emphasis on the interlocking relationships among Japanese automakers and parts suppliers within keiretsu networks in determining global production sharing of Japanese automakers. The findings suggest that the extent and modality of production sharing by Japanese automakers are significantly different compared to their counterparts in the United States and Western Europe. In particular, for Japanese automakers overseas production by their subsidiary plants is far less important in determining parts and components exports from Japan, given the general tendency of their part suppliers to internationalise their operations following the automakers.