Polyurethane/polythiophene (PU/PTh) blends and nanocomposites were prepared by solution mixing and in situ polymerization, respectively and were investigated for mechanical, thermal, electrical and shape memory properties. Formation of blends and composites was supported by FTIR analysis. Surface morphology of prepared samples was clarified by scanning electron microscopy (SEM). Homogeneous morphology of the composites was observed compared to blends due to well dispersion of NH2 functionalized MWCNTs attributed to introduction of urea linkages between the functionalized nanotubes and the NCO-terminated PU. Smooth morphology of the composites resulted for the significant improvement of the mechanical properties. Thermal stability of the blends and composites was found increased with PTh content. According to differential scanning calorimetry (DSC), an increase in glass transition, melting and crystallization temperature was observed for composites with PTh addition. Maximum shape recoverability (92 %) was exhibited by the PU/PTh composite with 1 wt. % PTh loading.