The abrasive flow finishing (AFF) process is a nonconventional finishing process that allows the use of a semi-solid viscoelastic polymeric mixture containing abrasive particles for removal of burrs, deposition, geometry optimization, and stress relieving of complex shaped components, internal cavities, dies, and difficult to reach surfaces. This article employed a one-way AFF process to improve the surface quality of spiral bevel gear (SBG) made up of 20MnCr5 alloy steel. A unique fixture was prepared for holding the spiral bevel gear, and restrictions were created inside the fixture to guide flow of abrasive contained finishing medium over curved surface of flanks. The SBG was finished using previously optimized AFF process parameters (i.e., size and abrasive concentration, extrusion pressure, and blending oil concentration), and the duration of finishing varied at two levels. The surface roughness profile and surface morphology of the finished gears were studied. The results showed considerable surface roughness reduction that will help enhance microhardness and improve motion transfer characteristics. This investigation proves that AFF is a simple, versatile, cost-effective, reliable, accurate, and general-purpose another gear finishing solution.