Rice husk (RH) reinforced polypropylene- (PP-) based composites were prepared by compression molding. The RH was treated with sodium hydroxide solution (1 wt%); then composites were prepared using varying percentages of RH (5 to 20 wt%). The thermomechanical, spectroscopic, and morphological properties of the prepared composites (RH-PP) were investigated. The scanning electron microscopic (SEM) analysis showed better interfacial adhesion between alkali treated RH and the matrix PP. The Fourier Transform Infrared (FTIR) spectra confirmed the chemical bonding.The results revealed that physical properties as well as thermal stability of the composites improved significantly with the addition of alkali treated RH in PP matrix.