Internal turning or boring operations have a history of being a cumbersome manufacturing process. The manufacturing industries are facing tougher tolerances of their product surfaces and a desire to process hard to cut materials and therefore the vibrations must be kept to a minimum. An increase in the productivity is also interesting from a production point of view. When cutting in pre-drilled holes the boring bar is usually long and slender and is thereby inclined to vibrate destructively concerning the machining result. The knowledge of the vibrations involved in boring operations and active control of external turning operations, have given a good basis for the active control solution in boring operations. The active control solution is based on a standard boring bar with an embedded piezo ceramic actuator placed at the peak modal strain of the boring bar. An accelerometer is also included in the design, mounted as close as possible to the cutting tool. The control algorithm is a filtered X LMS algorithm built on a feedback approach since the original excitation, the cutting process, cannot be observed directly. Preliminary results show reduction of the vibration in the boring bar by up to 30dB.