Stainless steels (SS) are used in a variety of precision, scientific, and industrial applications. All demand excellent surface properties for better functional performance of the products made by SS. Analysis, modeling, and optimization of machining of SS can result in process parameter combinations which facilitate to obtain better surface properties while machining SS using conventional processes. This paper reports the investigation on surface roughness (mean roughness depth) of SS304 machined by conventional turning using TiAlN/TiN coated tools under the influence of green lubricant. In this work total nine experiments with two replicates each have been conducted by varying three important machining parameters i.e. cutting speed, depth of cut, and feed rate at three levels each. A detailed effect of process parameters on mean roughness depth is discussed. Analysis of variance study is also reported. Process parameter optimization resulted in the optimum value 4.81 µm of mean roughness depth.