In this present study experimental investigation has been carried out to mitigate the NOx emission in 20% Annona biodiesel-diesel blend (A20) operated diesel engine by addition of antioxidant additives. The antioxidant additives used in the present study are p-phenylenediamine (PPDA), A-tocopherol acetate (AT) and L-ascorbic acid (LA). The addition of antioxidant additives to A20 blend did not cause and negative effect of properties of A20 blend. According to the test results, antioxidant additives are effective in controlling the Oxides of nitrogen (NOx) emission in diesel engine. Result shows that 250 mg concentration of PPDA additive with A20 blend was optimum for NOx mitigation up to 25.4% when compared to that of diesel without any major modification. (C) 2019 Elsevier Ltd. All rights reserved.