This study reports the feasibility of reusing glass fibre waste resulting from the thermolysis of polyester fibreglass (PFG) to produce a glass-ceramic material. PFG was treated at 550ºC for 3 h in a 9.6 dm3 thermolytic reactor. This process yielded a solid residue (≈68 wt.%), an oil (≈24 wt.%) and a gas (≈8 wt.%). The oil was mainly composed of aromatic (≈84%) and oxygenated compounds (≈16%) and had a fairly high gross calorific value (≈34 MJ kg-1). The major PFG degradation products were styrene, toluene, ethylbenzene, α-methyl styrene, 3-butynyl benzene, benzoic acid and 1,2-benzenedicarboxylic acid anhydride. The gas contained basically CO2 and CO; the hydrocarbon content was below 10 vol%. The higher gross calorific value of the gas was low (26 MJ Nm-3). The solid residue (97 wt% fibreglass, 3 wt% char) was converted into a glass-ceramic material. For this, a mixture consisting of 95 wt% of this solid residue and 5% Na2O was melted at 1450ºC to obtain a glass frit. A powder glass sample (<63 µm) was then sintered and crystallized at 1013ºC, leading to the formation of a glass-ceramic material composed of wollastonite and plagioclase s.s. with possible building applications.