A BiFeO3 thin-film was prepared from a solution by deposition on a Pt/TiO2/SiO2/Si substrate via a spin coating process and was subsequently annealed at 300 °C for 1 h to afford a non-crystallized BiFeO3 thin-film. Locally crystallized BiFeO3 nanodots were formed in the non-crystallized BiFeO3 thin-film via a local crystallization process using an atomic force microscope tip heated to 550 °C. By controlling the local heating time, ferroelectric BiFeO3 nanodots with different diameters ranging from 65 to 120 nm were obtained. The ferroelectric properties of the BiFeO3 nanodots were further investigated by studying the local ferroelectric switching behaviors and local piezoelectric d33 hysteresis loops using a piezoresponse force microscope.