This paper presents the performance of a piezoelectric Synthetic Jet Actuator (SJA) in quiescent flow. Pulse jet velocity and vorticity were taken as the parameter to evaluate the performance of SJA. PIV measurements on the jet flow at the orifice exit of a round SJA were conducted by varying the oscillating in frequency and voltage. The location of 5mm above orifice was identified as the optimum location for maximum pulse jet measurements. The maximum pulse jet velocity and vorticity obtained were 18.77 m/s and 242.5s-1. The PIV experiment showed that by varying oscillating frequency at fixed input voltage, the performance of  SJA was greatly affected by Helmholtz resonance. While in the investigation of varying input voltage at fixed oscillating frequency, diaphragm defection was the parameter that affects the performance of the SJA. Besides, PIV measurement showed that the flow patterns of vortex structure formation were affected by the oscillating frequency and pulse jet velocity.