The main objective of this present novel work is to investigate the performance, combustion and emission characteristics of biodiesel derived from the tamarind seed through the transesterification process as potential alternative feedstock for the diesel engine. The physio-chemical properties of tamarind seed methyl ester (TSME) were evaluated experimentally and compared with the base fuel. Test fuels were prepared in 3 concentrations such as B10 (10% tamarind seed oil and 90% diesel), B20 and B30.Experiments were conducted at a constant speed, the injection timing of 23° crank angle and compression ratio 17.5:1 with varying load conditions to investigate the diesel engine characteristics. TSME 20 shown better thermal efficiency (34.41%) over diesel which is 1.17 % higher and also it produces lower emissions of CO, HC, and smoke opacity. N-Amyl alcohol (NAA) is used as a fuel additive for the optimum blend of TSME20; added in 5% and 10% concentration on the volume basis. From the analysis of experimental data, the use of fuel additives significantly reduces the smoke opacity by 29.49 % for TSME20 NAA 10% blend in addition to the reduction of carbon monoxide and hydrocarbons emissions; however, the specific fuel consumption and the oxides of nitrogen were marginally increased.