Two fresh commercial pharmaceutical products containing ferrous sulfate such as Tardyferon® and Fenules® were studied by X-ray diffraction and Mössbauer spectroscopy. The obtained results demonstrated that each product contains iron compounds assigned to (i) FeSO4 × H2O and FeSO4 × 4H2O in Tardyferon® and probably two FeSO4 × H2O compounds with some tiny variations in the iron local microenvironments in Fenules®, and (ii) one ferric compound which was unidentified for Tardyferon® but identified as ferric acidic iron sulfate for Fenules®. A water free ferrous sulfate declared by the manufacturer was not found in Fenules.