We have prepared gadolinium doped europium sulfides, Eu1-xGdxS for a doping range of 0 <= x <= 0.1 by thermal decomposition of the precursors Eu(S2CNEt2)(3)Phen/Gd(S2CNEt2)(3)Phen with respective ratios. Electron doping provides indirect evidence for the magnetic coupling through carrier electrons in magnetic semiconductors. Based on the magnetic properties, we determined that the paramagnetic Curie temperature, Theta p, varies with doping level, in a similar way to Eu1-xGdxO exhibiting a significant increase at low doping levels. All materials have been characterized by X-ray powder diffraction, magnetic measurements, ICP-MS, and TEM.