Effort towards prospective utilization of dairy waste scum oil methyl ester (DSOME) is extremely pronounced as a promising sustainable unconventional fuel for diesel engine as they have intrinsic oxygen content emits less HC and CO emission and contradictorily increases the NOx. In this regard, the present study elucidates the influence of engine exhaust gas recirculation (EGR) on diesel engine performance, combustion and emission characteristics operated with DSOME-B20 (20% dairy scum biodiesel, by volume). The brake thermal efficiency (BTE) and brake specific fuel consumption (BSFC) are appreciably improved for 5% and 10% EGR in comparison with 15% EGR rate. Mainly, about 49-57% of NOx can be reduced with 5-15% EGR rate but increasing EGR rate more than 10% dilutes the fresh intake air hence reduces the NOx and increases the HC, CO emissions. Hence use of 5-10% EGR in diesel engine is advantageous to get considerably improved performance and reduced HC, CO and NOx emissions.