In order to update the review published in Tissue Antigens in 1997, we present here a new overview on microsatellites in the HLA region, including additional information, with focus on the following points: * Description of 103 microsatellite characteristics in the HLA region, 50 markers having been newly described since 1996. * An integrated map of the HLA region, including microsatellites and some HLA genes, revealing an important microsatellite density in the MHC (Class I, Class II and Class III regions). * A synthesis of microsatellite analysis in disease studies, summarizing results of microsatellite approaches in 24 pathologies, including autoimmune diseases, HLA-associated or HLA-linked diseases and cancers. * Other applications of HLA region microsatellites in population or transplantation studies.