The viewing characteristics of normally scattering polymer dispersed liquid crystal (PDLC) illuminated by guided light were studied. Luminance inversion occurred at viewing angles of more than 40 degrees for the polarization component parallel to the plane of incidence while contrast ratio was more than I at all angles for the polarization component perpendicular to that plane. The luminance inversion was caused by the refractive index mismatch for the polarization component parallel to the plane of incidence even when an electric field was applied. By controlling the polarization of scattered light, we could suppress the luminance inversion.