The present work investigates the effect of 1,4-dioxane additive on improving the diesel engine performance and emissions reduction using jamun biodiesel-diesel blend (JA20). The 1,4-dioxane is mixed with JA20 in different proportions ranging from 5ml to 10ml such as JA20-5ml and JA20-10ml (99.0% of JA20 + 1.0% of 1,4-Dioxane). From the results, it is observed that the brake thermal efficiency (BTE) for JA20-10ml is improved when compared to that of JA20 without additive at full condition. Further the hydrocarbon (HC), carbon monoxide (CO), oxides of nitrogen (NOx) and smoke emissions for JA20-10ml is reduced by 29.1%, 19.8%, 16.77% and 25.16% respectively when compared to that of JA20 at full load condition. Hence the JA20-10ml blend are the appropriate blend to improve the performance is better and reduced exhaust emissions from diesel engine without any engine modification.