The notion of green practices has become strategic important for many companies. Due to the increased concern about environmental sustainability, green practices are emphasized not only by governments but also by companies (Mitra and Datta, 2014). Globalization has also extended the scope of green practices. As firms rely more on their supply chain partners to obtain competitive advantage, green practices have been extended from single firms to the supply chain (Ghadimi et al., 2015; Zhu and Sarkis, 2004). For example, a Hong Kong toy manufacturer went bankrupt because it was sued by its US customers for using toxic paints purchased from a supplier (Ang, 2007). Accordingly, an increasing number of firms, especially large multinational corporations, are experiencing greater pressure from stakeholders to incorporate green practices into operations and supply chain practices (Rueda et al., 2017; Wilhelm et al., 2016; Zhu et al., 2017). In line with this trend, many studies have been conducted to understand the antecedents and results of green practices in terms of companies’ economic and environmental performance (Sharma and Vredenburg, 1998; Subramanian and Gunasekaran, 2015; Walker et al., 2008). These studies address the concept of green supply chain management (GSCM), which is defined as the application of environmental management principles to the entire set of supply chain activities, including design, procurement, manufacturing, assembling, packaging, logistics, and distribution (Handfield et al., 1997). In a thorough literature review by Walker et al. (2008), internal and external drivers and barriers to GSCM practices are identified in prior studies. Although great progress has been made concerning the drivers of GSCM practices in recent years, several issues remain unresolved. First, there are few studies on the cost considerations driving GSCM practices; existing studies focus on outside pressures, such as the government and customers (Yu and Ramanathan, 2015). These few studies are case-based, and there is a need for further investigation of the impact of cost drivers conducted with a large sample. Second, very few studies have investigated the cost and customer motivations for GSCM implementation simultaneously. It would be interesting to understand how cost and customer drivers individually and simultaneously influence GSCM practices (Sarkis et al., 2011). Finally, extant studies focus on various drivers of GSCM practices with limited consideration of their contingent effects of firm characteristics. For example, there are debates on “whether SMEs are able to do good-enjoy high social and environmental performance – given their struggles to do well – to even survive given the high failure rate” (Arend, 2014). As such, a comparative study of large and small companies is needed to examine these firms’ differences in adopting GSCM practices.