To determine the possibility of using leather waste as reinforcing filler in the thermoplastic polymer composite, acrylonitrile-butadiene-styrene (ABS) as the matrix and leather buffing powder as reinforcing filler were used to prepare a particulate reinforced composite to determine testing data for the physical, mechanical, and thermal properties of the composites, according to the filler loading in respect to thermoplastic polymer. The ABS and leather powder composites were prepared by the extrusion of ABS with 2.5, 5, 7.5, 10, 12.5, and 15 wt % of leather powder in corotating twin screw extruder. The extruded strands were cut into pellets and injection molded to make specimens. These specimens were tested for physicomechanical properties like tensile and flexural strengths, tensile and flexural modulus, Izod and charpy impact strength, abrasion resistance, Rockwell hardness, density, Heat deflection temperature (HDT) and Vicat softening point (VSP), water absorption, and thermal degradation analysis. The incorporation of leather waste powder does not affect the tensile, flexural strengths, Izod impact strength, abrasion resistance, Rockwell hardness, density, HDT and VSP values drastically. However, the tensile modulus, tensile elongation, and charpy impact strength values are reduced significantly. (c) 2006 Wiley Periodicals, Inc.