The purpose of this study was to evaluate the effect of different chemical fungicides application as seed treatment on growth, plant attributes and grain yields and incidence of diseases of Indian mustard. The field experiments was carried out in a randomized block design with three replications, consisting of 13 treatments namely no soaking control, water soaking, 1% KCl, 1% K2SO4, 1% CaCl2, 1% NaCl, carbendazim 50% WP, mancozeb M-45, KCl + mancozeb M-45, K2SO4 + mancozeb M-45, CaCl2 + mancozeb M-45, NaCl + mancozeb M-45, carbendazim 50% WP + mancozeb M-45. The result revealed that considerably maximum growth attributes (plant height, dry weight/plant, branches/plant, crop growth rate and relative growth rate), plant attributes (siliqua/plant, seeds/siliqua and test weight) and yields (seed, stover and biological) of Indian mustard observed when seeds treated with carbendazim 50% WP + mancozeb M-45 which were significant comparing with the rest of the treatments while it remained at par with K2SO4 + mancozeb M-45, KCl + mancozeb M-45 and mancozeb M-45. Seed treated with carbendazim 50% WP + mancozeb M-45 presented an increment of 111.96 and 95.67% in seed yield, 35.08 and 34.28% in stover yield and 48.72 and 45.8% in biological yield of crop as against to the no soaking control and water soaked treatment, respectively. In respect to percentage of disease incidence, maximum severity of white rust disease and alternaria blight diseases were observed under no soaking control and water soaked treatment. Minimum severity of white rust and alternaria blight diseases were recorded when seeds treated with carbendazim 50% WP + mancozeb M-45. According to our results, carbendazim 50% WP + mancozeb M-45 is the recommended treatment for seed before sowing that led to reducing white rust of leaf and alternaria blight diseases and enhancing the yields of crop with significant increase.