paper deals with the study on the effects of iron oxide nanoparticle (Fe2O3) additives when added to Mahua methyl ester (MME) blend on the emission, combustion, and performance characteristics of a four-stroke, single-cylinder, common rail direct injection diesel engine working at a fixed speed (1500 rpm) and varying operating scenarios. Doping is done in various proportions to the iron oxide nanoparticles with the help of a homogenizer and ultrasonicator where the cationic surfactant used is CTAB (cetyl trimethyl ammonium bromide). The fuels used for the experimental study are denoted as given (MME20 + Fe2O340, MME20 + Fe2O380 and MME20 + Fe2O3120). The experimental study revealed that while using the nanoparticle additives blended biodiesel (i.e., MME20 + IONP80) the number of harmful pollutants like smoke (5.38%), HC (6.39%), carbon monoxide (10.24%) and NOx, etc. have reduced to a considerable extent and there was a commendable improvement in the BTE by 8.8%. So, we can summarize that when biodiesel and nano additives are blended the combustion and performance of the engine was improved considerably and pollutant emissions were decreased.