The noise properties of phase sensitive amplifiers based on degenerate four-wave mixing in optical fibers are studied taking into account the quantum noise amplification, the amplitude and phase noise properties of the pump sources. An analytical tool is presented for the direct calculation of the amplifier noise figure also verified by extensive numerical simulations. The signal power dependence of noise figure is both analytically and numerically accented. The need for high speed and precise phase locking is also revealed in order to diminish the effect of phase noise on the noise properties of the amplifier.