Chemical cleaning or scale removal of boilers, heat exchangers etc., involves the dissolution of metal oxides, which are corrosion products from the base metal, Iron oxides mainly hematites and magnetites are commonly found in the case of Fe based alloys due to corrosion. The decontamination of primary system surface of water-cooled nuclear reactors, in particular Pressurized Light Water Reactor (PWR)/Pressurized Heavy Water Reactor (PHWR) involves the dissolution of iron oxides formed under reducing coolant chemistry environment ca. magnetite type of oxide matrix. Thus in the present study, the dissolution characteristics of Cr-substituted (0-20 at% Cr) magnetites (c.s.m) in V(II)-EDTA formulation at 353+/-5 K are reported. The oxides employed were prepared synthetically by co-precipitation method, moderately sintered and physicochemically characterized. The dissolution rate coefficient, k(1) and the percentage of dissolution were determined. The oxidative pre-treatment of these oxides employing viz., AP, NP and HMnO4 had resulted in improved dissolution.