Aziridines undergo smooth ring opening with a range of nitriles in the presence of 10 mol % of phosphomolybdic acid supported on silica gel (PMA-SiO2) under mild reaction conditions to afford the corresponding imidazolines in good yields and with high regioselectivity. The use of silica gel as solid Support facilitates an easy recovery and reuse of the catalyst thereby making the process quite simple, more convenient, and cost-effective.