The aim of this study is to synthesize novel I-131 labeled estrone derivatives that may have therapeutical potentials on Estrogen Receptor rich tumors. Two radiolabeled estrone derivatives, [I-131]2-iodo-3-methoxy-estra-1,3,5-trien-17-one and [I-131]4-iodo-3-methoxy-estra-1,3,5-trien-17-one were synthesized. Ether amino estrone derivatives were obtained from estrone in three steps by means of diazonium compounds. Tissue distribution studies exhibited receptor-mediated uptake in target organs in female Albino Wistar rats. Maximum uptakes for 2-iodo[I-131]-3-methoxy-estrone are in stomach, pancreas, intestines and uterus. A similar biodistribution profile was obtained for 4-iodo[I-131]-3-methoxy-estrone. However 2-iodo-3-methoxy-estra-1,3,5-trien-17-one has higher uptake in stomach, kidneys, pancreas, and intestines than 4-iodo-derivative.