The rise dynamics of a large particle in a 2-D vibrated bed of small grains is studied both experimentally and using a Molecular Dynamics simulation technique. The large particle is tracked as it moves upward in the bed and the velocity and acceleration of the particle are deter mined. Results suggest an important influence of the relative density of the large particle as well as the height of the background bed on the dynamics of the rising particle. (C) 2006 Elsevier B.V. All rights reserved.