Emissions evolved from the pyrolysis and combustion of used polyester fabrics were studied at different temperatures between 650 and 1050 °C in a laboratory scale reactor, to analyze the influence of both temperature and reaction atmosphere on the final products. More than 160 compounds, including carbon oxides, light hydrocarbons, and polycyclic aromatic hydrocarbons, have been identified and quantified. Benzene is the organic compound evolved with the highest yield. On the other hand, polychlorodibenzodioxins and -furans and dioxin-like polychlorinated biphenyls (PCBs) were also analyzed in the material and in the exit gas produced in the combustion, under fuel-rich conditions, at 850 °C. A total of 3.9 pg WHO-TEQ/g (toxic equivalence established by the World Health Organization), corresponding to a value of 1.1 to the dioxin-like PCBs, was found in the sample, while for the combustion run, a total of 17.9 pg WHO-TEQ/g was obtained, where dioxin-like PCBs only represent a value of 0.4 pg WHO-TEQ/g. The levels of polychlorodibenzo-p-dioxins, polychlorodibenzofurans, and dioxin-like PCBs obtained show that this waste could be used alone or probably with other fuels in incineration plants with energy recovery.