Sodium potassium niobate (Na0.5K0.5)NbO3 (NKN) ceramics were selected as one of lead free piezoelectric materials. These materials exhibit attractive properties, i.e., very large coupling coefficients and piezoelectric coefficients. The limitation of phase stability during sintering causes difficulty in preparing dense NKN ceramics. In this study, the effect of calcination and sintering temperatures, dwell time and heating rate on phase formation of the NKN powders was investigated. Cold isostatic press (CIP) technique along with the suitable firing schedule were utilized to improve the green and fired densities of NKN specimens. Phase formation of calcined powders and sintered specimens were determined using x-ray diffraction (XRD) technique. Microstructure of sintered pellets were examined by scanning electron microscopy (SEM). Dielectric, ferroelectric and piezoelectric properties were also investigated and the results were reported.