Research experiment was carried out under the field conditions during the rabi season of 2023-2024 at Central research field SHUATS Prayagraj, UP, India. The management of mustard aphid, Lipaphis erysimi (Kalt) was done using different treatments and benefit cost ratio of all the treatments were calculated. One spray was applied to protect the crop from Lipaphis erysimi using randomized block design with three replications. The observation of mustard aphid, Lipaphis erysimi 24 hours before (Pre-treatment) and 3rd, 7th, and 14th day after spraying (Post-treatment) were recorded for computing the per cent population reduction of pest. The different chemicals and biopesticides treatments revealed that Imidacloprid 17.8% SL (87.21%) shows the highest per sent reduction and was the most effective treatment followed by Cypermethrin 10% EC (84.31%), Nisco sixer plus (78.06%), Bacillus thuringiensis (73.02%), Beauveria bassiana (2×108 CFU/ml) (70.02%), Verticillium lecanii 1.15% WP (68.78%) the least per cent reduction was observed in Neem oil 5% EC (64.85%). The highest crop production, at 38.33 q/ha on average was recorded in Imidacloprid 17.8 SL with cost benefit ratio of (1:9.71) followed by Cypermethrin 10% EC 34.00 q/ha with (1:8.54) C:B ratio, Nisco sixer plus 31.66 q/ha with (1:7.22) C:B ratio, Bacillus thuringiensis 28.33 q/ha with (1:6.53) C:B ratio, Verticillium lecanii 1.15% WP 26.00 q/ha with (1:6.07) C:B ratio, Beauveria bassiana (2×108CFU/ml) 26.66 q/ha (1:6.04) C:B ratio, Neem oil 5% EC 21.66 q/ha with (1:4.64) C:B ratio and control 15.00 q/ha with (1:3.93) C:B ratio.