This work focuses on the combination of the complementary physical properties of multiwalled carbon nanotubes (MWCNTs) and poly(3-octylthiophene) (P3OT)/polystyrene (PS) polymer blend. The characterization of MWCNTs/P3OT/PS hybrid system performed by Fourier transform infrared spectroscopy, ultraviolet (UV)–visible absorption, and electrical measurements show interesting effects. Optical results demonstrate that the addition of MWCNT to P3OT/PS matrix blend will enhance the UV–visible absorption and insignificantly affect the optical energy gap of P3OT/PS matrix; this can be explained in terms of a reduced photo-induced charge transfer in such composite system. This study shows that incorporation of 5 wt% functionalized MWCNTs onto P3OT/PS polymer blend will convert this material from insulator to conductor and at this level of MWCNTs content, MWCNTs will form a network inside blend matrix with low capacitor element and high resistor element effects.