In the turning operation chatter or vibration is a frequent problem, which affects the result of the machining, and, in particular, the surface finish. Tool life is also influenced by vibration. Severe acoustic noise in the working environment frequently occurs as a result of dynamic motion between the cutting tool and the workpiece. In all cutting operations like turning, boring and milling vibrations are induced due to the deformation of the workpiece. This implies several disadvantages, economical as well as environmental. Many different solutions to minimize the problem have been developed but the fundamental problem is still there. The true nature of the vibrations, its causes, and implications were revealed in a doctor’s thesis in 1999, [1]. This has led to a break through in this research area. Since then, through recent research results at Blekinge Institute of Technology, a new approach to controlling vibrations in cutting operations in a lathe has been implemented in a product called Acticut®, developed by Active Control Sweden AB. This new method controls vibrations in the cutting direction using embedded sensors and actuators and a filtered-x LMS algorithm. This paper will discuss the application but also the algorithm and its main numerical properties to accomplish a good result, still maintaining its stability properties.