Abstract The formation of international co-operative arrangements with different scopes and structures has been growing in the international system. Brazil has frequently participated in these groups, forming a complex diplomatic framework where it coexists and interacts with regional blocs, international organisations, groups, and coalitions. Therefore, the purpose of this article is to investigate the commercial effects provoked by the international co-operative arrangements, observing in particular two cases from the Brazilian point of view: IBSA (India-Brazil-South Africa Group) and CPLP (Community of Portuguese Language Countries). The theoretical constructs of the New Institutional Economy formed the basis of the interpretation of the data, and the literature that explores new mechanisms of external insertion of emerging countries was highlighted through the diplomacy oriented towards the South-South axis. The methodology comprised the study of two cases, bringing together both quantitative and qualitative indicators based mainly on the official reports of the Brazilian government and sectoral analyses produced by trade associations. The intrabloc trade evolution was performed through a cluster analysis considering the exports and imports of each of the cases investigated in relation to Brazil. The results reached showed an increase in trade transactions between member states.