Mechanical and morphological properties of pure polypropylene (PP) polypropylene/calcium carbonate (PP/CaCO3) and polypropylene/cashew nutshell powder (PP/CNSP)are reported in this work. The composites were prepared by compression moulding technique. The compressed moulded articles that is the PP, (PP/CaCO3) and (PP/CNSP) of different compositions (10/90, 20/80, 30/70, 40/60, 50/50, 60/40, 70/30, 80/20) were characterised for mechanical properties, water absorption capacity, structural characterisation and morphological arrangements. Comparative studies was made on the mechanical properties of the pure polypropylene (PP), polypropylene/calcium carbonate (PP/CaCO3) and polypropylene/cashew nutshell powder (PP/CNSP). Mechanical properties such as tensile strength, Young‟s modulus and percentage elongation at break, Hardness behaviour and Impact resistance of both PP/CaCO3 and PP/CNSP composites increased with increment of filler weight content (10-50g). It was noted that the specimen samples of ratio50/40 PP/CaCO3 and PP/CNSP had the highest tensile strength, when compared with other sample. These specimens could bear loads of 1075N and 468N with extensions of 4.44mm and 6.12mm respectively. Decrease in the mechanical properties were noted on continuous addition of both fillers, with drastic reduction of the mechanical properties at (70g and 80g) fillers weight except hardness that slightly increased at all the filler loading (10-80g). The surface sorption characteristics of calcium carbonate and cashew nutshell powder have been investigated and the highest percentage was recorded at 20/80 of PP/CNSP (100%). Scanning electron microscopy (SEM) revealed that, both 60/40 PP/CaCO3, PP/CNSP and 50/50 PP/CaCO3, PP/CNSP are completely compatible at which there are no phases that are grossly separated. X-ray diffraction analysis showed that, the incorporation of the two fillers into the neat polypropylene decreased the crystallinity of the polypropylene and the crystallinity decreases with increasing filler‟s loading.