Foam injection molded parts exhibit a so called integral foam morphology which is represented by a cellular core structure surrounded by compact skin layers thus leading to a high weight specific bending stiffness. One mayor disadvantage of these parts is the inadequate surface quality, due to the presence of silver streaks, which limits the use of foam injection molded parts for visible applications. To overcome this hindrance, insert molding between skin layers can be applied. In general, the thermal conductivity of such inserts is low, hence, the thermal conditions while formation of the integral structure are changed. The aim of this study is to evaluate systematically the influence of low heat conductive inserts on morphology of foam injection molded parts. A physically (N2) foamed polypropylene is injected in-between two inserts (heat conductivity 0.2 W/Km). The thickness of the inserts as well as the distance between the inserts is varied. Foam morphology is detected applying light microscopy. It is shown that with increasing thickness of inserts the thickness of the compact skin layers of the integral foam is decreasing, due to lower heat transfer to the mold. Furthermore, a higher spacing between the inserts at constant insert thickness, which results in greater volume for foaming leads to increasing cell size, due to slower stabilization, thus increasing cell coalescence.