This article describes the experimental results for the stability of ferroelectric phase III of potassium nitrate (KNO3) at room temperature. To ensure the stability of ferroelectric phase III of potassium nitrate, we have prepared the composite films of potassium nitrate with polyvinyl fluoride (PVF) in the relative amount of 50-50 wt% using melt-pressing. The structural and electrical properties have been carried out. X-ray diffraction (XRD) has been used to identify the crystalline phases. The ferroelectric polarization hysteresis loops also show that the value of remanent polarization (P-r) is 5.5 C cm(-2) at room temperature. The switching current transient behavior was also investigated and indicates the presence of ferroelectric phase in the composite films. Capacitance versus temperature (C-T) measurements have been used to identify the phase transition temperature during heating and cooling, which supports the Curie-Weiss behavior. POLYM. ENG. SCI., 2013. (c) 2012 Society of Plastics Engineers