A survey of weed flora of cotton and clusterbean in south-western Haryana revealed that a total of 22 species were found to infest cotton crop, out of which 7 were grassy, one was sedge and 14 were broad leaf weeds. On the basis of IVI values, Trianthema portulacastrum, Dactyloctenium aegypticum, Echinochloa colona, Digera arvensis and Cyperus rotundus were found highly associated with cotton crop in all districts. T. portulacastrum alone constituted 48.7-56.8% of total weed flora with IVI values of 58.1-72.7 in all the districts, was the most dominant weed of cotton crop. Similarly cluster bean crop was found to infest with 25 major weeds of which 9 were grassy, 2 were sedges and 14 were broad leaf weeds viz., Digera arvensis, Cleome viscosa T. portulacastrum, Cyperus rotundus, Physallis minima, D. aegypticum, Corchorus tridens, Mollugo verticillata and Cucumis callosus. Digera arvensis constituting 43.2 to 69 % of total weed flora alone was the most dominant weed of cluster bean crop in all the districts except Bhiwani and Mahender Garh where C. viscosa was the most dominant weed with a relative density of 34.4 and 27.9 % and IVI values of 41.4 & 33.3, respectively. Among grassy weeds, Dactyloctenium aegypticum was the major grassy weed in all districts except in Mewat where Echinochloa colona was the most dominant weed with IVI value of 27.9. Mollugo verticillata, a weed of loamy sand soils showed its presence in Bhiwani, Mahender Garh, Jhajjar and Rewari only