Curie temperature (T C) of the ferromagnetic compound Sr 2 FeMoO 6 can be modified by increasing the itinerant electrons at the Fermi level. Nd doping increases the electron density but the charge neutrality should be taken into account. In this work, a series of double perovskites Sr 2−y NdyFe 1+x Mo 1−x O 6 (y = 0.0, 0.25, 0.5, 0.75 and 1.0) for both cases, the off-stoichiometric (x = 0) and the stoichiometric (x > 0 with x = y/2) one, were synthesized via solid state route and discussed in detail. A crystalline structure transition was confirmed by X-ray diffraction analysis, showing a change of the lattice parameters and the unit cell volume as a function of Nd doping. It was also found that the nominal valence in Fe is mainly Fe 3+ and in Mo is Mo 4+. The T C increases continuously with Nd doping in the stoichiometric case. The increase of the T C follows a competition with the substitution of Sr 2+ ions by Nd 3+ ions and the charge neutrality considered in our system.