Nowadays, high levels of automation, integration and flexibility are required to increase the competitiveness of manufacturing industries. In this perspective, an increasing interest in unmanned, intelligent machining systems has emerged. Ideally, future production systems will be designed to automatically perform complex tasks, such as planning and optimization of tool trajectories and cutting parameters, tool collision detection and tool condition monitoring, effective suppression of vibrations and chatter. Self-excited chatter vibrations may arise during machining for specific combinations of cutting parameters. This detrimental phenomenon may cause abnormal tool wear or tool breakage, damage of tooling structure and spindle bearings, poor surface roughness and dimensional accuracy of the workpiece. In the last few decades, several methodologies and systems for chatter prevention, detection and suppression were proposed in technical literature and some of them have been already successfully implemented in innovative machine tools and tooling systems. The aim of this chapter is to introduce the problem and the modern methodologies for its solution. © 2015 by Nova Science Publishers, Inc. All rights reserved.