Institutional theory provided scholars from various backgrounds with powerful and effective theoretical tools to probe into the post-socialist transition economies over the last two decades. Researchers, particularly in the fields of international business, and small business and entrepreneurship, benefited significantly by drawing on neo-institutional perspectives to explore and explain the various effects of unstable institutional settings and embedded institutional factors on firm behaviour in these environments. However, it is highlighted here that the neo-institutionalist approach, and in particular the new institutional economics lens, tends to represent the most dominant approach utilized by scholars interested in post-socialist economies. While this perspective remains powerful and effective, this chapter proposes that research in this area can potentially benefit in important ways from expanding the boundaries of institutional analysis by integrating insights from two emerging but hitherto underexploited institutional perspectives, namely the varieties of transition approach, which is an alternative to the mainstream comparative capitalism, and a more actor-centred perspective on institutional change. It can be argued that the transition process in post-socialist states has not followed the once-anticipated linear progression towards Western models of capitalism. Despite the popularity of institutional approaches in studying transition economies, research on the transitional periphery within the broader realm of business studies has remained largely silent in acknowledging the divergent transition paths and the possible implications of this institutional divergence for firm behaviour. Furthermore, limited attention has been paid to the role of actors as agents of institutional change, including the mechanisms they deploy to achieve such change. Thus, integrating insights from comparative capitalism and theory of institutional change can enrich the current thinking on institutions and the firm in the transitional periphery by shedding new light on these important issues.