Diverse move has been attempted to use biomass as a filler for the production of biodegradable all-cellulose composites. In this study, cellulose fibrils (CFs) extracted from native African Napier grass (NG) fibres were used as fillers in cellulose matrix and made all-cellulose composites. Napier Grass Cellulose fibrils (NGCFs) loading was varied from 5 to 25 wt% in cellulose matrix in random orientation and the all cellulose composites were made by regeneration process. These composites were characterized by Fourier transform infrared (FFIR) spectroscopy, X-ray diffraction, thermogravimetric analysis, optical microscopy, and tensile testing. The FTIR spectra indicated not only the presence of minute amounts of hemicelluloses and lignin in the filler but also the possible interaction between the matrix and NGCFs. The crystallinity of the all-cellulose composites was found to be lower than that of the cellulose matrix. The thermal stability of the all-cellulose composites was found to be higher than that of the cellulose matrix and increased with NGCFs filler content The tensile strength of the all-cellulose composites though was lower than that of the cellulose matrix but still was higher than for commodity polymers. The all-cellulose composites can be considered for wrapping and mulching applications. (C) 2018 Elsevier B.V. All rights reserved.