Lead-free piezoelectric (K0.5Na0.5)NbO3 nanopowders were synthesized by urea sol gel combustion method using freshly prepared Nb2O5 center dot nH(2)O and alkali hydroxides as starting materials and urea as a fuel. The effects of metal cation/urea molar ratio and calcination temperature on the crystalline phase formation of (K0.5Na0.5)NbO3 were systematically investigated. The results showed that at a metal cation/urea molar ratio of 1:1, the single crystalline (K0.5Na0.5)NbO3 nanopowders, with an average grain size of 15 nm, were synthesized at calcination temperatures as low as 400 degrees C.