The aim of this paper is to develop an analysis of Hanging Topic and Hanging Topic Left Dislocation in Brazilian Portuguese. To do so, we adopt the framework of Segmented Discourse Representation Theory (SDRT), because it allows one to describe the rhetorical relations, and therefore to study the use contexts of some marked constructions. The corpus which is the basis of analysis of this research are the interviews published in the VEJA magazine in the 1970s, as well as Dialogues between Informant and Documenter (DID) provided by the NURC-SP project (Cultured Urban Linguistic Norm – São Paulo). From the data analysis, it was possible to notice a clear distinction between the uses of the constructions under investigation in the two corpora. We have noticed that hanging topics are discursive units per se, which relate to the context by a subordination relation and to the comment by Frame or Attribution. Hanging topics seem therefore to be pragmatically indistinguishable from frame-setting topics, once both exert the function of inaugurating complex discursive units, so as to preserve textual progression.