The present invention involves the manufacturing process of iron sucrose complexes. Iron sucrose is basically from the haemitinic therapeutic group. It is a complex between polynuclear iron (Fe+3) hydroxide in a sucrose molecule. The molecular weight of the iron sucrose complex is ranging from 34,000 to 60,000 Daltons. Iron therapy is necessary in the treatment of iron deficiency anemia. Iron sucrose complex is prepared by reacting ferric hydroxide with sucrose molecules in basic condition. Therapeutically active iron-containing compositions comprising iron in a form capable of increasing amount of hemoglobin in the blood. Intravenous is particularly employed for patients, who cannot tolerate oral iron therapy, are unable to adequately absorb dietary iron, or who suffer hematopoietic failure. The iron sucrose complex is free of substantial free of excipients. The main object of the present invention is to provide the simplest and cost effective method for the production of iron sucrose complexes.