The pseudo-binary TiO 2 -FeSbO 4 system was investigated by means of thermogravimetric analysis below 1673K in O 2 . Rutile-type solid solutions were synthesised at 1373K in O 2 by means of a solid state reaction between the two pure end members TiO 2 (rutile) and FeSbO 4 mixed in stoichiometric amounts. Thermal stability of the (Ti 2 x Fe 1 - x Sb 1 - x )O 4 solid solution increases with rutile content; equimolar (Ti 1 . 0 0 Fe 0 . 5 0 Sb 0 . 5 0 )O 4 solid solutions decompose at about 1673K forming a TiO 2 -enriched solid solution and FeSbO 4 , that subsequently decomposes into Fe 2 O 3 (hematite) and a volatile Sb oxide, probably Sb 4 O 6 . For compositions characterised by higher Ti content the decomposition temperature is higher than 1673K.