This article addresses corruption as a negative practice displaying the ‘darker side’ of social capital in Chinese guanxi and Russian blat/svyazi networks. It presents a conceptual framework integrating several research streams to establish a conceptual linkage between social network characteristics and three forms of corruption between business persons and public officials: cronyism, bribery, and extortion. We argue that the forms of corruption in a society are determined by the nature of social network ties and their underlying morality, with particularistic and general trust being key factors. Our framework depicts networks as three concentric circles representing three types of corruption resulting from their corresponding types of reciprocity: open, closed, and negative. We then apply the framework to the practice of guanxi in China and blat/svyazi in Russia. We propose that different network characteristics and different forms of corruption may help explain what we label the ‘China-Russia paradox’ of why corruption and high economic growth have co-existed in China, at least in the short term, but less so in Russia. We conclude with ethical and legal implications for doing business in those two transforming economies and offer suggestions for future research.