Syndecans, a family of heparan sulphate proteoglycans that are present in the cellsurface are involved in the control o fcel lproliferation, apoptosis and transfor-mation. Syndecans 1 and 2 have a central role in processes such as position control, invasion, angiogenesis and metastases ofseveral types of cáncer The expression of Syndecan 1 in epithelial cells, decreases when cells are transformed and acquire invasive properties. This decreased expression is associated to a bad prognosis. Syndecan 2, originally described in mesenchymal cells, favors cell apoptosis, increa-ses angiogenesis and controls the death of cáncer cells subjected to chemotherapy Both syndecans are present in basal and epithelial cells of prostate cancer Their lower expression is associated to more undifferentiated tumors. Disturbances in the expression and subcellular location of syndecans predict the relapse of localized tumors. Syndecans 1 and 2 can be considered tumor suppression genes and can be targetsfor new treatments. The detection of circulating fragments of these molecules could be useful for the early detection of prostate cancer.