We develop an efficient algorithm for handling collision events that is suitable for Discrete Particle Modeling (DPM) of dense gas-solid fluidization systems. We improve on previous strategies that are discussed in this paper as a byproduct. The core idea is centered on the use of dynamic crosswise linked data structures. This type of data structures enables an efficient updating and managing of lists of collision events associated with particles. In addition, a chained-hash-table strategy is proposed to efficiently process particle collision sequences. For systems of N-p particles. this strategy allows a complexity 0(1) time per collision regarding the event list handling operations (C) 2009 Elsevier B.V. All rights reserved.