Normative critiques of South-South relations assess the extent to which solidarity and cooperation are achieved among partner countries. However, they tend to overlook the role of inter-ethnic tensions in partnerships and the ways global South actors exercise agency in achieving cooperation. Transnational skilled migration between global South countries is an emerging context where South-South cooperation takes place. Using the case of Filipino skilled workers in Indian cities, this paper aims to ascertain the sort of tensions that characterise South-South relations and the manner in which actors work out cooperative partnerships. The concept of boundary work, a process of defining ‘us’ and ‘them’ and relating to others through a set of socio-cultural criteria (ASR 73:37-59, 2008), is deployed to analyse Filipino-Indian interactions in the workplace. Ethnographic data reveal that while ethnic moralities constitute boundaries and tensions between Filipino and Indian workers, they also become bases of affinity. Cooperation is achieved when Filipino and Indian participants engage in personal and mutually beneficial arrangements such as guru-student and patron-client relations. An ethic of reciprocity thus animates South-South cooperation. I conclude with some implications for global South partnerships.