Field investigion was carried out for two consecutive years 2009-10 and 2010-11 at Pantnagar (Uttarakhand) to study the bio-efficacy of ethoxysulfuron for the control of Cyperus rotundus (nutsedge) in sugarcane. Experiment consisted of six treatments, viz. doses of ethoxysulfuron 46.87, 56.25 and 60 g/ha, 2,4-D Na salt 1000 g/ha, three hoeing 30, 60 and 90 days after planting (DAP) of sugarcane and untreed control was laid out in randomized block design with three replicions. Ethoxysulfuron and 2,4-D Na salt were applied  at 3-4 leaf stage of Cyperus rotundus. Among the herbicidal treatments, the lowest weed density as well as dry weight of total weeds was observed with ethoxysulfuron 60 g/ha 3-4 leaf stage of C. rotundus  at both the stages at 30 and 60 DAA though the differences were non-significant when compared with its lower dose 56.25 g/ha, 30 and 60 DAA and 46.87 g/ha 60 DAA during both the year. Application of ethoxysulfuron 3-4 leaf stage of C. rotundus effectively controlled C. rotundus and broad-leaved weeds, viz. Trianthema monogyna, Digera arvensis, Cleome viscosa and Ipomoea spp. This herbicide any rate was not effective against grassy weeds. The highest cane yield was recorded with the execution of three hoeing at 30, 60 and 90 days after planting (DAP). Among the herbicidal trements, ethoxysulfuron 60 g/ha at 3-4 leaf stage of C. rotundus recorded maximum cane yield (82.3 and 86.8 t/ha), although it was at par with its lower dose 56.25 g/ha. The lowest cane yield was recorded with control.