Lead free ferroelectric Ba0.85Sr0.15TiO3(BST)thick films were successfully deposited by screen printing process on Ag-Pd/Al2O3 substrates. The microstructure of the samples was analyzed by scanning electron microscope (SEM)and X-ray diffraction (XRD). The thick films showed a good adhesion to the Ag-Pd/Al2O3 substrate, a porous microstructure and uniform thicknessesof about10 μm. The dielectric propertiesofBST thick films were studied over a wide frequency range (10-1 Hz to 106 Hz) and in a large temperature range from25°C to 350 °C. The AC conductivity inBST thick films was systematically investigated.Ferroelectric characterizations and tunability were also studied at room temperature by polarization cycles P(E) andcapacitance C(E) measurements. The high values of dielectric permittivity and tunability (67%) combined with low dielectric loss (tgδ) make Ba0.85Sr0.15TiO3 thick films one of the encouraging candidates for microwave tunable applications.