Field and pot studies were conducted during two rainy (Kharif) seasons of 2013 and 2014 to identify the effectiveness and optimum dose of mesotrione and atrazine combination for diverse weed flora management in maize. The weed control treatments evaluated in field experiment were pre-emergence atrazine 1000 g/ha and post-emergence 2,4-D-Na 1000 g/ha, mesotrione 120 g/ha and ready mixture of mesotrione with atrazine in ratio of 1:10 w/w (Calaris Xtra 275 SC) at 750, 875 and 1000 g/ha. The major weeds infested were Dactyloctenium aegyptium, Digitaria sanguinalis, Echinochloa crus-galli, Trianthema portulacastrum, Digera arvensis and Phyllanthus niruri. The uncontrolled weed competition reduced the maize yield by 38.7 to 54.0%. Mesotrione 120 g/ha was effective in controlling the broad-leaved weeds but was poor in controlling grass weeds. The weed control with pre-emergence atrazine 1000 g/ha was also not consistent. However, in pot and field studies, ready or tank mixture of mesotrione with atrazine was synergistic and superior in controlling weeds than to sole mesotrione and atrazine applications. The weed control efficiencies with ready-mixture of mesotrione + atrazine (1:10 w/w) at 875 and 1000 g/ha ranged 89-99%. Mesotrione plus atrazine at 875 and 1000 g/ha yielded (7.74-8.11 t/ha) significantly higher as compared to mesotrione 120 g/ha (5.83-5.96 t/ha), atrazine 1000 g/ha (5.93-6.70 t/ha) and 2.4-D-Na 1000 g/ha (3.82-5.30 t/ha) applications, as well as, untreated weedy check (3.73-4.76 t/ha). The results showed that mesotrione and atrazine combination has synergistic effect, which can be used for managing diverse weed flora in maize.