In recent years, there have been many modern engineering materials introduced recently which are hard, brittle and difficult to machine. These materials are very difficult to machine with conventional turning methods. Ultrasonic assisted turning (UAT) is a new non-conventional technique, used to remove an unwanted material to produce a desired product. Ultrasonically assisted turning (UAT) is an advanced machining technique, where a high frequency of vibration (frequency f ≈ 20±0.5 kHz, amplitude around a ≈ 20 μm) is superimposed on the movement of a cutting tool. In this method, high frequency electrical energy is converted into mechanical vibrations via a transducer or booster combination, which are transmitted through a horn or tool assembly. An ultrasonic vibratory tool (UVT) designed and analyzed using ANSYS® (one of the FE code) for the calculation of its natural frequency and working amplitude of vibration. Taguchi with TOPSIS method is used to optimize both cutting force and surface roughness to find the best possible machining parameters under the used experimental working condition in UAT.