An active vibration control system is proposed for suppressing the small amplitude random vibrations in flexible beams. Intelligent materials such as the piezoelectric ceramic PZT are used as the actuator and the piezoelectric plastic PVDF is used as the sensor. The characteristics of the physical system are identified by a parametric modelling technique. The linear quadratic Gaussian (LQG) algorithm is employed for the controller design. The controller is implemented on the basis of a floating-point digital signal processor. The experimental results obtained by using the active vibration control system show significant attenuation of white noise disturbance in the frequency range of approximately 100-800 Hz.