Since proteins are key effectors of plant responses to environmental cues, including recognition, signalling, transport and defence reactions, much interest has focussed on characterising proteins involved in the establishment and functioning of arbuscular mycorrhizal (AM) symbiosis. The recent development of high-throughput techniques in the model species Medicago truncatula is providing, step-by-step, a large-scale analysis of symbiosis-related proteins. Depending on the symbiotic stage and the abundance of mycorrhizal material, different proteomic strategies, which can be combined with other large-scale approaches (transcriptomic and metabolomic), can be used and are presented in this chapter. In addition to providing an update on AM related-proteomics research, our aim is to highlight proteomic strategies available to study AM symbiosis. Finally, further developments that can be expected from the most recent technical improvements in plant proteomics are discussed for this particular research area.