The major problem in all machining operations is chatter which constitutes excessive vibration between tool and the workpiece. Due to the generation of chatter, tool life, reliability and safety of machining operation will be shortening. Mechanical smart structures automatically can acknowledge to external loading such as fatigue loads, seismic loads and shock loads. The application of smart fluid such as Magnetorheological fluid has been the interface between electronic controls and mechanical system, which provides controllable damping force. One of the important characteristic of MR fluid is the ability to change from viscous liquid to semi-solids in milliseconds when exposed to a magnetic field. Experimental investigation has been carried out with different cutting speed, feed rate and depth of cut and varying input current ranges from 0 to 24 Volts. The input voltage modifies the magnetic field inside the coil of the damper where chatter mark in the workpiece has been suppressed. The main objective of this work is to recommend MR damper to suppress vibration and improve surface roughness. The optimum conditions to accomplish better damping effect for the mitigation of chatter has been identified and 50% of the chatter will be suppressed. The dynamic response of end milling cutter has been studied with and without the application of MR damper, and roughness parameters have also been estimated.