Abstract : The efficiency of dynamic dispatch is a major impediment to the adoption of multi-methods in object languages. In this paper, we propose a simple multi-method dispatch scheme based on compressed dispatch tables. This scheme is applicable to most existing object languages, and guarantees that dynamic dispatch is performed in constant time, a major requirement for some languages and applications. We provide efficient algorithms to build the compressed dispatch tables, and demonstrate the effectiveness of our scheme by real measurements performed on a large object-oriented application. Finally, we relate our scheme to existing techniques, including a detailed comparison with a recent proposal.