A ternary composite composed of two immiscible organic phases, polypropylene (PP) and polyamide-6 (PA), and talc as inorganic filler is studied in terms of mechanical properties and microstructure. Effect of different filler levels (10-30 % by weight) on tensile and flexural properties of each polymeric phase is examined while special attention is paid to immiscible PPPA blend. Mutual effect of compatibilizer and filler on properties is searched by selecting maleic anhydride grafted polypropylene (MA-g-PP) as compatibilizer. It is observed from SEM studies that inhomogeneous, course and elongated morphology of uncompatibilized composites is changed to well dispersed, fine and more homogeneous particle-in-matrix morphology via additional compatibilization effect. This unique microstructure is believed to be responsible for the improved tensile and flexural properties in blend composites.