Abstract: The invention relates to a type of radioimmuno-conjugates where the &agr;-radiators or the &bgr;-radiators are stably coupled to the antibody with or without the use of a complex-forming agent and wherein the radioisotope is not iodine and wherein the &bgr;-radiators are Yttrium-90, Rhenium-188, Rhenium-186, Copper-67, Holmium-166 and Samarium-153 and the &agr;-radiators are Astatine-211 or Bismuth-212 and wherein the MAb-moiety of the conjugate is derived either from the mouse, a human or other mammal and which can be either intact, fragmented, humanized or recombinantly manipulated. Furthermore, the invention relates to radioimmuno-conjugates where the MAb binds onto an extracellular antigen, which preferentially appears on cells of the haematopoietic system or where the MAb binds to an antigen at the surface of granulocytes or granulocyte-precursors, or both of these cell types, or were the MAb moiety of the conjugate binds onto an epitope or epitopes of CD 66, respectively CD 66 a, b, c and e.