Magneto-rheological (MR) fluid is a type of smart material which has ability to change its flow resistance on the application of magnetic field. This property of changing viscosity of the fluid due to application of magnetic field is utilized in the MR brake. MR brake typically consists of multiple rotating disks immersed in MR fluid and an enclosed electromagnet. The controllable yield stress produces shear friction on the rotating disks, generating the braking torque. Of late MR brakes have been explored for automotive applications. Literature review reveals that the torque output of MR brake is not sufficient for braking of mid-sized car. Hence, it is worthwhile to investigate its application for a two-wheeler where the braking torque requirement is low. This paper presents design and simulation of MR brake performance for its torque output. Design of MR brake involves deciding the configuration of MR brake in terms of number and sizing of disks, selection of MR fluid and design of magnetic circuit. The response of MR brake in terms of torque output with respect to influencing parameters like speed, current, number of disks, MR fluid properties and intensity of magnetic field can be observed with the help of simulation in order to save cost and time associated with experimental testing. MATLAB/SIMULINK software environment has been used for this simulation.