The pyrolysis of Ba(CF 3 COO) 2 ·nH 2 O at temperatures up to 1000°C, under flowing pure Ar, O 2 and O 2 saturated with water vapour, was extensively analysed. The existence of a:CF 2 diradical is inferred and the formation of HF is observed directly for the first time during a trifluoroacetic acid salt decomposition. High resolution thermogravimetry, differential scanning calorimetry, X-ray diffractometry and scanning electron microscopy indicated that the exothermic two-stage decomposition of the anhydrate salt occurs between 282 and 325°C, forming BaF 2 via an unstable CF 3 COOBaF intermediate. Fourier transform infrared spectroscopy revealed the influence of water on the reactions of the liberated gaseous products, identifying CF 3 COOH, HF, CHF 3 and CO 2 as the principal volatile species, with C 2 F 4 , C 2 F 6 , CO and SiF 4 also detected. The decomposition temperature is significantly lower than previously reported, which has implications for sol–gel processing.