The authors developed methods for the synthesis of coordination compounds of iron(III) with thiosemicarbazide (TSC).The compounds structure was proved by IR spectroscopy, conductometry, X-ray diffraction, and thermogravimetry. The authors found the bidentate coordination of TSC with iron(III) via sulphur and nitrogen atoms. Thermogravimetrically authors have established the proceeding of the complex decomposition in two stages. The first stage involves thermolysis of organic ligands with the formation of the corresponding iron salts; the second one includes decomposition of iron salts and formation of iron(III) oxide. Conductometrically we have established the synthesised complexes are strong electrolytes. X-ray diffraction shows the crystallisation of the complexes into orthorhombic syngonies. There are two structural units in the cell.