Ferroelectric thin films of bismuth-containing layered perovskite Bi4Ti3O12 have been fabricated by a metalorganic decomposition (MOD) method. Crack-free and crystalline films of ∼5000 Å thickness have been deposited on Pt/Ti/SiO2/Si substrates. Different heat treatments have been studied to investigate the nucleation and growth of perovskite Bi4Ti3O12 crystallites. If the same composition and final annealing temperature are used, films with different orientations are obtained by different heating schedules. These films show a large anisotropy in ferroelectric properties. Theoretical considerations are presented to suggest that nucleation control is responsible for texture and grain-size evolution. Moreover, the origin of the ferroelectric anisotropy is rooted in the two-dimensional nature of layered polarization.