Presence of vortices/phase singularities has been demonstrated in instantaneous generalized Stokes parameters (IGSP) of the field generated by illuminating a random phase screen with a polarization structured beam. Polarization structuring is achieved by focusing the vector beam with tilt in one of the orthogonal polarization components with respect to other. Spatially structured polarized beam is scattered by non-birefringent random phase screen placed at the focal plane of focusing lens. Field distribution of orthogonal polarization components are evaluated at the focal plane of second lens, and subsequently IGSPs are evaluated. Evaluations of the IGSPs are performed by varying one observation point r 2 with respect to a fixed reference point r 1 . Distribution of phase singularities is displayed in the phase map of IGSP. These singularities disappear in the spatially averaged generalized stokes parameters.