High temperature sensors are of major importance to aerospace and energy related industries. In this letter, a high temperature monolithic compression-mode piezoelectric accelerometer was fabricated using YCa 4 O (BO3) 3 (YCOB) single crystals. The performance of the sensor was tested as function of temperature up to 1000 ��C and over a frequency range of 100-600 Hz. The accelerometer prototype was found to possess sensitivity of 2.4��0.4 pC/g, across the measured temperature and frequency range, indicating a low temperature coefficient. Furthermore, the sensor exhibited good stability over an extended dwell time at 900 ��C, demonstrating that YCOB piezoelectric accelerometers are promising candidates for high temperature sensing applications. �� 2010 American Institute of Physics.