The electrical characteristics of ZnO thin-film transistors with high-k ͑Ba, Sr͒TiO 3 gate dielectrics are presented. The ZnO and ͑Ba, Sr͒TiO 3 thin films were deposited on Pt, exhibiting polycrystalline characteristics. The thin-film devices demonstrated transistor behavior over the range of 0-10 V with a stable threshold voltage of approximately 1.2 V. The field effect mobility, subthreshold slope, and on/off ratio were measured to be 2.3 cm 2 V −1 s −1 , 0.25 V / decade, and 1.5ϫ 10 8 , respectively. The measured transistor performance characteristics suggest that ZnO / ͑Ba, Sr͒TiO 3 structures are well suited for both polycrystalline thin-film transistors for display applications and future higher performance transistors based on single crystal ZnO.