Recently, there has been a growing concern for the environment and awareness of the negative impact of plastic waste on pollution. Today, synthetic polymers derived from petroleum are the main materials used for packaging. The large petroleum deposits are limited and cause global climate change, and the resulting synthetic polymers cannot be degraded in nature. For this reason, increasing emphasis is being placed on the development and use of biodegradable polymers. However, their wider application is still limited compared to synthetic polymers due to their poorer properties and more difficult processing. To overcome these shortcomings and facilitate processing, increasing attention is being paid to the preparation of polymer blends with the addition of nanofillers that have the desired properties that are important for the application. Polylactide (PLA) is currently one of the most studied environmentally friendly polymers produced from renewable resources. To expand its range of applications, it is often blended with thermoplastic starch (TPS). PLA / TPS blends exhibit a wide range of physical properties that can be controlled by changing the blending conditions and component proportions. Since the polymers are not miscible with each other, it is possible to increase their miscibility by adding nanofillers and thus improve the properties of the obtained polymer blends. In this work, the influence of nanofillers, ZnO, on the properties of PLA / TPS polymer blends with different component ratios was investigated. The thermal properties of the obtained blends were investigated using differential scanning calorimetry (DSC), thermogravimetric analysis (TGA) and thermal conductivity measurement techniques. The surface free energy of the components was determined by measuring the contact angle and the adhesion parameters were calculated. The mechanical properties were determined by tensile testing, and insights into the morphological structure were investigated by scanning electron microscopy (SEM).