Thin films of CuFe 2O 4 tetragonally distorted spinel ferrile were deposited by r.f. magnetron sputtering from a sintered target of the same composition in argon gas atmosphere. It was shown that traces of water in the sputtering chamber could affect the crystalline orientation of samples annealed at 450°C. In fact, traces of water favour the formation of <310> oriented films. The as-sputtered samples were made of very small crystallites (less than 10 nm in diameter), The films annealed at 450°C had crystallites of 20–30 nm diameter at their upper surface. No significant differences were apparent between the microsiructures of the annealed films despite their differing crystalline orientations. In contrast, the highest coercivities and Faraday rotations were measured for the (310) oriented samples. The deposited films were single-phase CuFe 2O 4 during the first 20 h sputtering. After this lime, as well as the fcrrilc, anotherphase, CuFeO 2, was revealed by X-ray diffraction. Sputtering of the target by oxygen allowed recovery of a pure ferrite phase on the deposited films.