Recently, nanomaterials obtained from biomass have gained attention due to their function and sustainability. Among bio-nanomaterials, cellulose nanowhisker (CNW) is one of the most potential materials for reinforcement of bioplastics due to its superior mechanical properties, biodegradability, and high aspect ratio. In the study, cellulose acetate composite was produced using CNW obtained under different conditions. There was a significant increase in the initial modulus of the composite with increasing CNW content, but there was no impact on the thermal stability.