The article presents preliminary work carried out to prepare and evaluate the blends obtained from an unplasticized poly(vinyl chloride) (PVC) compound, formulated with several amounts of TiO2 and an organosolv lignin. A series of blends in which lignin replaced partially or totally the TiO2 were made on a laboratory scale. The influence of lignin on the melt processing of the blends and on their stress-strain properties was studied. Dynamic mechanical analysis (DMA), differential scanning calorimetry (DSC), and scanning electron microscopy (SEM) were performed to examine the contribution of lignin to the properties of these blends. The possibility of a proton donor/proton acceptor interaction between lignin and PVC chains is discussed. This can arise due to the interaction between the carbonyl group of lignin and ct hydrogen of PVC or between hydroxyl groups of lignin and chlorine of PVC.