In the past ten years, stabilization of the phase morphology of immiscible polymer blends during melt compounding went through a new perspective by the use of inorganic nanoparticles as compatibilizers. Following the ideas of Ramsden [1] and Pickering [2] the stabilization of the minor phase could be achieved with solid nanoparticles located at the interface of the phases, lowering the interfacial tension and acting as a physical barrier to droplet coalescence. In this work, the location of the silica nanoparticle in an immiscible polymer blend is studied using quantitative optical microscopy, measuring the light scattering, i.e. turbidity, created by the use of hydrophilic and hydrophobic silica nanoparticles (hlSilica and hbSilica respectively) in an immiscible polymer blend. The light scattering at the polymer/polymer interface is minimized choosing a PS/PC immiscible blend which has minimal difference in their refractive indices. On the other hand the considerable difference in the refractive indexes of the chosen polymers and nanosilica would highlight the scattering effect of the silica nanoparticles if located at the polymer/polymer interface. The turbidity from neat PS/PC blends and some PS/PC/hlSilica systems were similar, showing only a small change in the turbidity in the range of the two polymers glass transition temperatures, which is an indication that the silica nanoparticle are dispersed inside the two polymer phases. However, the turbidity is greatly increased in the system PS/PC/hbSilica, containing the hydrophobic silica, which according to the wetting parameter should have the silica nanoparticles be located mainly at the polymer/polymer interface. [1] RAMSDEN, W., Proc. Royal Society of London, p. 156-164, 1903. [2] PICKERING, S. U., CXCVI. Emulsions. p. 2001-2021, 1907.