An optical scanning device and an image forming apparatus having the same include a light source, a deflecting system, an imaging optical system with at least one imaging optical element for imaging a light beam deflected by the deflecting system on a surface to be scanned, and at least one reflection type optical element disposed between the imaging optical element and the scanned surface, wherein the deflected light beam passes through a first transmission surface and a second transmission surface of the imaging optical element in this order and, after being reflected by the reflection type optical element, the light beam then passes through a third transmission surfaced and a fourth transmission surface of the imaging optical element in this order, and wherein a relation |øM/ø|