Genomes provide us with a blue print for the potential of a cell. However, the activity of a cell is expressed in its proteome. Full understanding of the complexity of cells demands a comprehensive view of the proteome; its interactions, activity states and organization. Comprehensive proteomic approaches applied to peroxisomes have yielded new insights into the organelle and its dynamic interplay with other cellular structures. As technologies and methodologies improve, proteomics hold the promise for new discoveries of peroxisome function and a full description of this dynamic organelle.