Recent progress in life science technology and the availability of much information on genes obtained by genome analysis has enabled us to analyze the changes of proteins on a large scale. Sets of proteins are called proteomes, and proteomics is the scientific field of proteome analysis including differential, post translational modification and interaction analyses. Various proteomic techniques, particularly two-dimensional gel electrophoresis (2-DE), mass spectrometry, protein chip methods, and surface plasmon resonance (SPR), are very useful for acquiring proteomes in cells, tissues and body fluid, and for analyzing interactions between a protein and other biofactors including proteins. A proteomic approach is also useful for determining biomarkers of diseases and key proteins involved in various stages of metabolism such as differentiation, cell cycle and apoptosis. Environmental pollutants including endocrine disruptors inhibit activities of various organs in wild animals and humans. Proteomic approaches could be very useful tools for elucidating the mechanisms of damage caused by environmental pollutants. In this review, we describe the application of a proteomic approach to the field of environmental medicine.