We investigate the ferroelectric properties of epitaxial BiMnO3 (BMO) nanosquares and thin films deposited by pulsed laser deposition techniques. The size of the BMO nanosquares is found to increase as the deposition time increases. The multiferroic BMO nanosquares exhibit ferroelectric and ferromagnetic characteristics. The BMO nanosquares with upward and downward ferroelectric polarizations exhibit low and high resistance states, respectively.