Proteomics has its origins in two-dimensional gel electrophoresis (2-DE), a technique developed more than twenty years ago. 2-DE has a high-resolution capacity, and was initially used primarily for separating and characterizing proteins in complex mixtures. 2-DE remains an important tool for protein identification, but is now normally coupled with mass spectrometry (MS), a technique which has advanced considerably in recent years. The recent completion of human genome project has produced a large DNA database which can be utilized through bioinformatics, and the next challenge for scientists is to uncover the entire proteome of a particular organism. The integration of genomic and proteomic data will help to elucidate the functions of proteins in the pathogenesis of diseases and the ageing process, and could lead to the discovery of novel drug target proteins and biomarkers of diseases. This review describes recent advances in proteomic technology and discusses the potential applications of proteomics in biomedical research.