Magnetorheological fluid based finishing process is particularly useful for finishing of optical materials. Magnetorheological (MR) fluid consists of magnetic particles, abrasive particles, carrier fluid such as water or oil, and additive. Under the influence of magnetic field, magnetic particles form chain like structure and they support abrasive particles to perform finishing. Stiffness and abrasive holding power of MR fluid significantly depend on the size of magnetic particles while concentration and type of abrasive particles are also important parameters which affect the quality of finished surface. An experimental investigation is carried out to study the effect of size, concentration and type of abrasive particles as well as the size of magnetic particles on material removal rate and % change in surface roughness (Ra) of final finished surface of single crystal silicon workpiece. A rheological study in terms of yield stress is also carried out to analyze MR fluid behavior under magnetic field.