Abstract The machining of multiphase (ferrite-bainite-martensite) microalloyed steel was carried out in a high speed lathe to assess the machinability. The mechanical properties of multiphase (ferrite-bainite-martensite) microalloyed steel were analogous to those of quenched & tempered steels. The influence of machining parameters such as cutting speed, feed rate and depth of cut on cutting force and surface roughness was studied. The result shows that the feed rate and depth of cut influence more on cutting force and for surface roughness the only influencing parameter is feed rate. Optical and scanning electron microscope were used to find the microstructure and surface topography.