Magnetic nanocrystals exhibiting outstanding coereivity values can be dispersed in polymer-based composites tor use in micro actuators. micro pumps and sensing devices. In the present work, cobalt ferrite nanocrystals were synthesized under size-controlled conditions in aqueous phase and incorporated into a polyimidc matrix at various volumetric loads. Synthesized 20nm-eobalt ferrite single crystals, which exhibited a coercivity of 2.9kOc at room-temperature. were dispersed in polyimidc precursor (Dupont PI2555) and cured to develop the polyimidc matrix in the resulting nanocomposites. Produced films were characterized by Fourier transform infrared spectroscopy, X-ray diffraction and vibrating sample magnetomctry, which confirmed the formation of the nanocomposite. As expected, the saturation magnetization in the nanocomposites varied according to the Polyimide/Fcrrite weight ratio, while coereivity remained at the value corresponding to pure cobalt ferrite nanocrystals.