A field experiment was conducted during the Rabi 2004-05 and 2005-06 to study the effect of planting pattern and weed conrol practices on weed dynamics and productivity of sweet corn. Planting pattern of 60 x 20 cm with 83,333 plants/ha proved to be very effective in suppressing weeds, recording the lowest density of grasses, sedges and broad-leaved weeds at 30 and 45 days after sowing (DAS). At harvest also, it resulted in the lowest total weed density, weed dry weight with the highest weed control efficiency (WCE) and was at par with 75 x 16 cm. These two planting patterns were found to be significantly superior to 60 x 25 cm and 75 x 20 cm with 66,666 plants/ha. Though the highest cob length and green cob weight of sweet corn were realized with 60 x 25 cm, the green cob (13.9 and 13.2 t/ha) and green fodder yield (17.6 and 16.6 t/ha) were found to be the highest with 60 x 20 cm and resulted in higher net returns (Rs. 24, 987 and 23,024/ha). Pre-emergence application of atrazine @ 1 kg/ha followed by (fb) hand weeding at 30 DAS provided significant weed control during the citical crop-weed competition period in sweet corn upto 45 DAS. It also recorded the lowest total weed density and dry weight with the highest weed control efficiency at harvest, which resulted in the highest green cob yield (14.2 and 13.4 t/ha) and green fodder yield (18.0 and 17.1 t/ha) of sweet corn with enhanced net returns (Rs. 25,251 and 23,221/ha) and B : C ratio, though at par with two hand weedings at 15 and 30 DAS and pre-emergence application of atrazine @ 1 kg/ha fb post-emergence application of paraquat @ 0.5 kg/ha at 30 DAS. Uncontrolled weed growth throughout the crop growth period reduced the green cob yield to an extent to 40-42% during both the years of experiment.