As operating factors play an important role in engine emissions and performance, it is important to explore the simultaneous impact of various operating factors on engine performance and emission responses. Taguchi method was used in order to determine the suitability of using n-pentanol in spark ignition engine and to determine the optimum operating conditions with fewer experiments instead of many experiments. Engine load, n-pentanol percentage and ignition advance were selected as engine operating variables. Three different levels were determined for each of the selected engine variables and an experimental design was created using the Taguchi method. Taguchi method proposed L-27 (3 <^> 3) orthogonal array experimental design for three different variables with three different levels. According to the graphs of signal-to-noise ratio obtained with Taguchi design, simultaneous optimum results of all responses were generally determined as high n-pentanol percentage, average ignition advance and average load. According to results, Taguchi design method is an effective method with the aim of defining the impact rates of engine operating parameters and to optimize engine operating variables for best engine performance and emissions.