It has been established that the polarization properties of light can be effectively utilized in modifying the characteristic of the imaging system. As a matter of fact, the diffraction properties of the lens get modified when it is masked by polarizing devices. It is therefore well expected that characteristics of an imaging system also be modified by utilizing polarization properties of light. This calls for a systematic study of the effects of variation of polarization on diffraction pattern of different kinds of slit including polarizing devices. In this paper we study the Fraunhofer diffraction pattern of a slit using polarized light having variable state of polarization across it. © Optical Society of India 2011.