Much effort has been devoted m recent years to develop processes for the rejuvenation of metal fouied spent catalysts from residue hydroprocessmg umts In dus paper we report the Influence of addmg femc salts to some organic a&s in selecttve extraction of foulant metals from the spent catalyst pnor to decokmg Leachmg expenments were camed out usmg two &fferent orgamc ac%-ls, namely, oxalic acid and tartanc acrd with and without fernc nitrate ad&hon The spent and the treated catalysts were characterized and the Improvements in surface area, pore volume and HDS achvlty as a result of leaclung w&h Qfferent reagents compared The studies revealed that m the absence of femc salts, the actds showed very poor acttvlty for leachmg foulant metals from coked spent catalyst Ad&bon of femc mtrate enhanced the leaching efficiency of each acid to a &fferent degree The selechvity for the removal of the major metal foulant (vanadmm) was &fferent for chfferent leaching reagents The enhanced leaching by the femc mtrate.-organic acid system has been explamedm terms of a syneqqsac mechamsm mvolvmg ox&mg and complexmg reactions The improvements in surface area and pore volume recovery was found to be related to the extent of vanadmm removal from the catalyst. The HDS activity of the catalyst also increased stgmficantly by leachmg of the deposited metals The study showed that oxalic aad-fernc nitrate reagent was supenor to other reagent systems in terms of selectlvlty for vanadmm leachmg as well as for surface area, pore volume and activity recovery