How does the SME internationalisation network develop across institutional distance and why? In order to understand and explain the process of SME internationalisation network development between a developed economy (the UK) and an emerging one (China), a conceptual research framework was first developed from the integration of theories of small firm internationalisation (Child and Hsieh 2014; Coviello 2006; Jones and Coviello 2005), social networks (Burt 1995; 2011; Jack 2010; Slotte-Kock and Coviello 2010) and institutions (North 2009; Peng 2003; Scott 2008). Welch et al.'s (2011) 'contextualised causal explanation perspective’ was then applied in an empirical context, through the in-depth study of three cases of SME network development between Scotland and China, which resulted in findings that underline the interconnectedness between formal and informal institutions and their effects on the phenomenon. The thesis ultimately offers a causal explanation process model of SME internationalisation network development across institutional distance, answering calls from the internationalisation literature (Jones et al 2011) for a greater understanding of how and why institutions (Eden 2010) - and informal institutions (Sartor and Beamish 2014) in particular – matter.