This paper examines the argumentative interactions between the Brazilian Supreme Court (Supremo Tribunal Federal - STF) and other courts in order to clarify how the STF uses other court’s rulings. Using an analytical framework, the authors sought to identify whether the STF’s Justices build their reasoning based on arguments mentioned by other courts’ rulings, including foreign and transnational ones. Qualitative analysis revealed weak interactions between the STF and other courts since in most cases Brazilian Supreme Court’s Justices merely mention prior rulings, without necessarily discussing the reasoning of other courts’ decisions in order to use them as part of its own reasoning. Among the eleven cases analyzed, only in four cases we found some influence of the rulings mentioned in the definition of the legal issue and in the judicial response.