Ferroelectric and piezoelectric behavior in odd-odd polyamide 11,11 are successfully detected for the first time. The maximum coercive field (E-c) of 90 MV/m, and a remnant polarization (P-r) of 40 mC/m(2) are obtained at room temperature. A piezoelectric strain coefficient (d(33)) value as high as-23.9 pC/N has been found in stretched polyamide 11,11 film. The structural change of samples before and after poling is investigated by wide-angle X-ray diffraction patterns, differential scanning calorimetry, and Fourier transform infrared spectroscopy. The results indicate that the nature of the ferroelectricity originates from amide group dipoles in the c-form crystal regions. Hysteresis behavior appears to result from the crystallites reversal mechanism. (C) 2014 Wiley Periodicals, Inc.