Barium zirconate-titanate (Ba(ZrxTi1−x)O3, BZT) films with thickness around 60 nm were deposited on Ir substrates using RF magnetron sputtering. The effect of zirconium atomic fraction (x = 0.14 to 0.7), substrate temperature (380 °C to 550 °C) and oxygen partial pressure (0 to 5 mTorr with total pressure 30 mTorr) on leakage current, dielectric constant and dielectric dispersion (capacitance reduction with increasing frequency) was studied. We found that the Zr/Ti ratio played a crucial role in determining the dielectric constant and dispersion. The dielectric constant varies from 26 to 168 while dispersion ranges from 0.80 to 2.58 % loss in capacitance (dielectric constant) per decade of frequency. Low leakage currents (< 1× 10−7 A/cm2) were observed.