Antibodies have proven to be exquisite investigation tools in the field of life sciences. They also constitute one of the oldest and most successful biological products for diagnostics and therapeutics. This review investigates the current use of antibodies in target discovery. To address this topic in a larger context, established and emerging technologies that are expected to contribute to target discovery will first be examined. These technologies include: mass spectroscopic analysis of proteins, protein-protein interaction and other network analysis approaches, as well as protein and antibody arrays. The potential of antibody engineering and the ANTIBIOMIX technology will then be discussed; antibody therapeutics, however, will not be examined.