Abstract The barium–strontium–titanate (BST, Ba 0.64Sr 0.36TiO 3) thin films have been prepared by the sol–gel method on a platinum-coated silicon substrate. The resulting thin films show very good dielectric and pyroelectric properties. The dielectric constant and dissipation factor for Ba 0.64Sr 0.36TiO 3 thin film at a frequency of 200 Hz were 592 and 0.028, respectively. The dependence of the capacitance as a function of the voltage shows a strongly non-linear character, and two peaks characterizing spontaneous polarization switching can be clearly seen in this curve, indicating that the films have a ferroelectric nature. The capacitance changed from 495 to 1108 pF with the applied voltage in the −5 to +5 V range at a frequency of 100 kHz. The peak pyroelectric coefficient at 30 °C is 1080 μC/m 2 K. The pyroelectric coefficient at room temperature (25 °C) is 1860 μC/m 2 K, and the figure-of-merit of this film is 37.4 μC/m 3 K. The high pyroelectric coefficients and the greater figures-of-merit of Ba 0.64Sr 0.36TiO 3 thin films make it possible to be used for thermal infrared detection and imaging.