We report the enhancement of ferroelectric properties in vanadium-doped Bi 4Ti 3O 12 (BIT) thin films deposited by a sol-gel method. Compared to the undoped BIT, V-doped BIT (BTV) showed higher polarizations and a better fatigue resistance as reported in ceramic systems recently [Noguchi et al., Appl. Phys. Lett. 78, 1903 (2001)]. BTV showed a remanent polarization (2P r) of 15.9 μC/cm 2, higher than the value for BIT, 12.5 μC/cm 2. The polarization of the BTV thin film capacitor decreased by 19%, while that of the BIT decreased by 23% after the fatigue test with 4×10 10 switching cycles.