The results of the leaching of vanadium(V) from the mixture after potassium metavanadate synthesis from KCl and spent vanadium catalyst in the presence of steam were presented. Spent vanadium catalyst was obtained from the waste storage of a chemical plant producing sulfuric acid(VI) by the contact method. The reaction mixture was leached using different solutions: 1 M Na2CO3, 20% CO(NH2)2, 15% NaOH, 15% KOH, 2 M H2SO4. The effect of time and temperature was studied. The results showed that for reaction mixture leached for 4 h at 303 K in the presence of 15% sodium hydroxide solution at a liquid:solid ratio of 10:1, the extent of leaching of vanadium(V) was 95.43%.