An investigation on the effect of filler geometry/shape on the dynamic mechanical properties of polymers was conducted. The viscoelastic damping matrix chosen was SBR and the fillers chosen were graphite, aramid, and carbon short fibers. The study was conducted by taking a control base compound of 20 parts N330 carbon black-filled styrene butadiene rubber (SBR). Dynamic mechanical thermal analyzer was used to investigate the viscoelastic damping of the rubber composites at low dynamic strain levels. Compressive hysterisis at moderate degree of strain were evaluated for all the composite samples to probe into their high strain static damping properties. SEM was used to investigate the matrix-fiber interaction and distribution of the fillers. Investigations demonstrated that the matrix-filler interface plays a major role in energy dissipation. The amount of interface was analyzed by considering the half height width of tan delta peak. Fiber matrix interaction parameter was calculated from the tan delta(max) values for matrix and composite. It was observed the interaction parameter and the low strain tensile stress values register similar trend. Aramid short fibers were most effective in more energy dissipation than other fillers under consideration. (C) 2008 Wiley Periodicals, Inc. J Appl Polym Sci 111: 264-272, 2009