This study examined effects of applying a magnetic field (up to 2 kG) on the magnetic properties of epitaxial NiFe2O4 (NF) thin films during deposition. The NF films were deposited on Y0.15Zr0.85O1.93 (YSZ) buffered Si (001) substrates using pulsed laser deposition (PLD). Although application of magnetic field during deposition affected neither the crystal structure nor orientation of the NF thin films, it improved magnetic properties. The saturation magnetization (Ms) of NF thin films deposited at 500°C and 600°C without application of a magnetic field was as low as 40 emu/g. However, that of NF deposited under magnetic field of 2 kG got to bulk Ms (50.3 emu/g). The TEM observation results revealed that the anti-phase boundary (APB) density decreased by application of the magnetic field during deposition. Results show that magnetic properties of NF thin films are controllable using the magnetic field during deposition.