Freeform complex surfaces have become an essential part of many devices to perform the required functions. Many of these components require nanometer-level surface finish to perform the desired functions efficiently. In this work, an attempt has been made to improve the external morphology of freeform surfaces, especially knee joint, by abrasive flow finishing process. A uniform mirror finished surface with improved finishing rate is achieved for stainless steel knee joint. Extrusion pressure is varied to reduce final surface roughness value and finishing time. Experimentally, good surface finish ranging from (Ra) 42.9 to 62.5 nm is achieved at various locations of the knee joint which are within the recommended American Society for Testing and Materials standard (100 nm) of knee joint prosthesis. Effects of abrasive flow finishing process parameters are investigated to develop "know how" of the process on the freeform surfaces. Abrasive flow finishing process has given 76.56% reduction in finishing time as compared to the time required by "ball end" type tool used for finishing knee joint.