Endosseous implant to be applied to human or animal bone, said implant having a surface made from a selected metal or a selected metal alloy or a ceramic, whereby said metal resp. metal alloy is selected from chromium, niobium, tantalum, vanadium, zirconium, aluminium, cobalt, nickel, stainless steels or an alloy thereof, said surface having a smooth or rough texture, characterized in that said surface has been treated with at least one pharmaceutically acceptable organic compound carrying at least one phosphonic acid group or a derivative thereof preferably a pharmaceutically acceptable salt or ester or amid thereof and method for producing said implant.