The components having freeform surfaces have been widely used in aerospace, automobile, medical, consumer products and die/mold industries. many of these components require nanometer surface roughness to meet specific requirements in their application domain. as the complexity of the surface increases, time and cost of finishing also increases. therefore, a cost effective and efficient finishing process is necessary to make these components reliable. a magnetorheological fluid based finishing tool is developed for nanofinishing of knee joint implant having complex freeform surfaces. different types of magnetorheological fluids and various finishing steps are proposed to reduce finishing time. surface characteristics of knee joint implant are studied using surface roughness measuring instrument and atomic force microscopy before and after finishing. significant reduction in surface roughness (the best final ra value obtained = 28 nm) is observed on the component after finishing. the surface roughness obtained in different surfaces is well within the values recommended in astm standard for total knee joint prosthesis.