In this study, alpha-Fe2O3-ZnO mixed particles were incorporated into the poly methyl methacrylate (PMMA) matrix by using solvent casting process. In order to prepare a powder mixture, mechanical milling process was used. alpha-Fe2O3 synthesized by precipitation method and ZnO nanoparticles were mixed with same amount and milled with planetary type ball milling machine for 1 h. Morphological and structural examinations of the produced powders were conducted with scanning electron microscopy (SEM) and X-ray diffraction (XRD). Optical and dielectrical properties of composite materials produced with different amount of reinforcement (0.1 wt%, 0.5 wt% and 1.0 wt%) were examined by using UV-Vis spectrophotometry and vector network analyzer (VNA). It was observed that optical transmittance reduced with increasing reinforcement amount. Dielectric properties of produced pellet composites with 4 mm thickness were conducted between 70 and 110 GHz and the results showed that the real and complex permittivity and dielectric loss values of PMMA/alpha-Fe2O3 is higher than those of neat PMMA, PMMA/ZnO and PMMA/alpha-Fe2O3-ZnO.