The preparation and properties of hybrid materials based on poly(lactic acid)/poly(lactic acid-co-glycolic acid) (PLA/PLGA) blends using microcrystalline cellulose (MCC) and organophilic silica (R972) as fillers have been investigated. Hybrid materials were manufactured by solution casting using chloroform as solvent to prepare films. R972 was incorporated in a ratio of 3wt%, and MCC was added in ratios of 3, 5, or 7wt% with respect to the weight of the polymeric matrix. Films were prepared with only MCC addition or with MCC and R972 combined. Properties of the films were evaluated by X-ray diffraction (XRD), nuclear magnetic resonance, differential scanning calorimetry (DSC) and mechanical property measurements. The results show that each filler, when added individually or in combination, affects the structure and final properties of the films differently. MCC acts as a nucleating agent for the crystallization of the polymeric matrix. An increase in the MCC content increased the crystallinity of the films. This effect became more pronounced with silica addition. The domain distribution curves showed PLA/PLGA blends to be homogeneous, which was further confirmed by DSC. An improvement in the mechanical performance was observed with MCC addition, especially when silica was added together with cellulose. POLYM. ENG. SCI., 57:464-472, 2017. (c) 2016 Society of Plastics Engineers.