Lead-free piezoelectric thin films of NaNbO 3 –BaTiO 3 were fabricated on Pt/TiO x /SiO 2 /Si substrates by chemical solution deposition. Perovskite NaNbO 3 –BaTiO 3 single-phase thin films with improved leakage-current and ferroelectric properties were prepared at 650°C by doping with a small amount of Mn. The 1.0 and 3.0mol% Mn-doped 0.95NaNbO 3 –0.05BaTiO 3 thin films showed slim ferroelectric P–E hysteresis and field-induced strain loops at room temperature. The 1.0 and 3.0mol% Mn-doped 0.95NaNbO 3 –0.05BaTiO 3 films showed remanent polarization values of 6.3 and 6.2μC/cm 2 , and coercive field of 41 and 55kV/cm, respectively. From the slope of the field-induced strain loop, the effective piezoelectric coefficient (d 33 ) was found to be 40–60pm/V.