GdSr2RuCu2O8 oriented films have been deposited on SrTiO3 (100) substrate by d.c. sputtering. Films deposited in pure oxygen atmosphere have shown c‐axis oriented GdSr2RuCu2O8 phase after an appropriate ex‐situ thermal treatment in oxygen atmosphere. X‐ray diffraction, scanning electron microscopy and energy dispersive spectrometry have been used to check the crystal structure, the morphology and the composition of the samples. The investigations have been performed before and after the oxygen annealing pointing out an increased structural order.The samples have been characterized magnetically in the range from 1.9 to 400 K. A selected sample has exhibited a possible ferromagnetic transition with a Curie temperature of about 150 K. All the samples measured by transport measurements show a semiconducting behaviour down to 4.2 K. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA …