This empirical study of Taiwan’s textile and apparel manufacturers investigates the relationships between green supply chain management (GSCM) drivers (organizational support, social capital and government involvement) and GSCM practices (green purchasing, cooperation with customers, eco-design and investment recovery). It also studies moderating effects by institutional market, regulatory and competitive pressures. Through hierarchical moderated regression analysis, the results of this research show that (1) except for investment recovery, the other three GSCM practices are positively affected by GSCM drivers; (2) investment recovery is positively affected only by organizational support; (3) market pressure has no moderating effects on most of the relationships between GSCM drivers and GSCM practices; (4) regulatory pressure has positive moderating effects on most of the relationships between GSCM drivers and GSCM practices; and (5) competitive pressure has negative moderating effects on most of the relationships between GSCM drivers and GSCM practices. Finally, the implications of this study and future research are discussed.