The piezoelectric constant of 50 pm V-1 and pyroelectric constant of 20 µC m-2 K-1 were obtained for polyurea thin films (∼ 300 nm) prepared by vapor deposition polymerization from methane diisocyanate and diaminofluorene. The pyroelectric signal and the infrared spectrum indicate that the dipoles of urea groups in the polymer were highly oriented normal to the surface of the aluminum substrate to induce remanent polarization without a conventional poling process. The piezoelectricity observed for the film is due to the coupling effect of the remanent polarization and electrostriction. No ferroelectric polarization reversal was observed for the film up to 390 K.