The present work was focused to investigate the influence of injection timing, load torque and engine speed on the performance and emissions and to optimize these parameters using response surface methodology (RSM) for Jatropha biodiesel operation in a diesel engine. For this investigation, experimental parameters were designed by using full factorial design with 27 runs. The effect of variation of injection timing, load torque and engine speed on BSFC, BTE, P max, CO, HC, NO emissions and smoke were investigated experimentally. Response surface models have been developed using experimental data. The optimal values of performance and emission parameters: BSFC, BTE, P max, smoke density, CO, HC and NO emissions are 0.2875 kg/kWh, 30.96%, 65.79 bar, 4.26, 0.0076 vol%, 5.27 and 321.69 ppm, respectively, at fuel injection timing, load torque and speed of 342.6 CAD were 11.4 Nm and 1801 rpm, respectively, for the Jatropha biodiesel engine using RSM.