In this study, composites based on polyvinyl chloride (PVC), pulp fiber (PF), and wood flour (WF) were made by injection molding. The effects of two variable factors, namely the filler form and filler loading level, on the composite physical properties were examined. The result clearly showed that the major part of water absorption was due to water absorption of PF. It was found that the water absorption in the lignocellulosic material base composites is significantly higher than the neat PVC. Besides, the water absorption increased sharply with increasing cellulosic filler loadings in the composites. In case of hybrid composites, the rate of water uptake correlated with percentage weight of WF, lower WF (higher PF) loadings in composites exhibit higher rate of absorption. The higher onset of degradation temperature indicates the improved thermal stability of the samples. In other words, the result clearly illustrates that the thermal property of the composites increases after using PF and further increases after addition of WF.