A field investigation was carried out during the rainy seasons of 2001 and 2002 to test the bioefficacy of post-emergence herbicides for controlling weeds in direct seeded rice (Oryza sativa L.). All the herbicidal treatments significantly r educed the density and biomass of weeds and increased grain yield of the crop significantly over unweeded check. Uncontrolled growth of weeds caused 68% reduction in the crop yield as compared to weed free in both the years of investigation. Pre-emergence application of butachlor at 1500 g/ha followed by one hand weeding produced maximum grain yields in both the years among all herbicidal weed control treatments, which were comparable to those obtained with post-emergence application of pyrazosulfuron at 25 g/ha, chlorimuon+metsulfuron at 4 g/ha, butanil 4000 ml/ha and bentazone at 1250 g/ha. The same treatments also resulted in maximum reduction in the density and growth of the weeds. Application of fenoxaprop reduced the population of grassy weeds, whereas butanil and pretilachlor reduced the grassy as well as broad leaved weeds. Post-emergence application of chlorimuon+metsulfuron, bentazone and pyrazosulfuron were most promising for controlling broad leaved weeds and sedges in direct seeded drilled rice.