Hydrothermal route was used in the preparation of Fe-doped CdO nanoparticles with 3, 5, 7 and 10 wt% and their structural and magnetic properties were investigated. Structural characterization using powder X-ray diffraction confirmed the single phase cubic symmetry of these nanoparticles. Particle size decreased monotonically with increasing the dopant ion concentration. The microstructure of the synthesized samples was studied by a high-resolution transmission electron microscopy (HRTEM) which confirmed the nanocrystalline nature of the samples. A vibrating sample magnetometer provided the hysteresis curves of all samples. Pure CdO reveals ferromagnetic behavior while antiferromagnetization is observed for all Fe-doped samples. Large coercivity as well as large area for the sample x = 0.05 is achieved.