The thermal behaviour of different mixtures of coal-tar binder pitches (CTP, Softening points KS 70, 80, 90) and sulfur (9 and 18% in weight considering CTP) and coke (CTP 30%wt, 70%wt.) was studied by thermogravimetric analysis, pyro-oxidative analysis and optical microscopy of the solid residues from heat treatment (room temperature to 420-degrees-C at 6-degrees-C/min). The thermal behaviour of CTP/sulfur blends deeply depends on sulfur amounts and on chemical composition of CTP (QI content, hexane solubles). Of particular interest is a mixture with 18%wt. sulfur. In this case, a sol-gel transition seems to be invoqued to explain the role of sulfur on the behaviour of blends. The authors note the positive role of sulfur in lower amounts (9% in weight) on the mesophase formation. For CTP/coke/sulfur blends, the most relevant phenomenon is the appearance of quinoline insoluble (QI) zones (50-10 mum) associated with cracks for high sulfur percentages. Such zones were also observed in CTP/sulfur mixtures but for lower concentrations (< 9% in weight). Probably, the adsorption mechanism of the CTP on the coke during the mixing process could explain the highest consumption of sulfur. ft seems that the development of these zones is related to a modification of the mechanical properties of the solids.