Piezoelectric accelerometers fabricated from Lead-Zirconate-Titanate (PZT) thin films are expected to achieve higher sensitivities and better signal-to-noise ratios (SNR) in comparison with capacitive and piezoresistive accelerometers. This paper will present, for the first time, the fabrication and performance of piezoelectric, bulk-micromachined accelerometers using PZT thin films operating in the d33-mode. Using sol-gel techniques, 0.6 mm thick PZT films with high piezoelectric coefficients were deposited. Measurements on these PZT films show a remnant polarization Pr < 19 (mu) C/cm2, dielectric constants Er > 800, and d33 coefficient of 120 pC/N. The PZT accelerometers operating in the d33 mode were successfully fabricated. Interdigitated capacitors were used to achieve the d33 mode of operation and deep reactive ion etching was used to define the proof-mass of the accelerometers. Measurements on these accelerometers show sensitivities ranging from 0.85 - 1.67 mV/g with resonance frequencies ranging from 22.4 - 15.4 kHz respectively. In addition to the improved sensitivity, advantages of d33-mode accelerometers include use of thinner PZT films, and the ability to optimize the impedance of the device to achieve a higher SNR. The performance of MEMS d33-mode accelerometers will also be compare with the previously reported d31-mode accelerometers using PZT thin films.