One of the most interesting properties of agrofilled polymer composites is their light weight. Polypropylene composites containing six different agrofillers were prepared in a mixer, and their properties were examined in terms of the density of the fillers and composites. The densities of the composites increased with the level of filler but did not show a direct relationship with the density of the fillers used. This probably happened because of the different degrees of filler densification during processing. The composites showed decreased tensile strength and increased elastic modulus with filler loads, and the specific mechanical properties showed similar trends. However, the addition of maleated polypropylene improved the tensile strength and decreased the density; this improved the specific properties of the composites filled with cane, wood, and bamboo. (C) 2010 Wiley Periodicals, Inc. J Appl Polym Sci 117: 400-408, 2010