An efficient method for the synthesis of spiroquinazolinones was developed using isatoic anhydride, hydrazides and cyclic ketones, through a rapid one-pot three-component reaction in the presence of SBA-Pr-SO3H under solvent-free conditions. SBA-Pr-SO3H was an efficient heterogeneous nanoreactor with a pore size of 6 nm which can be easily handled and removed from the reaction mixture by simple filtration