Comparative efficacy of different pre-emergence herbicides Stomp 330 E (pendimethalin), Stomp 455 CS (pendimethalin), Top 33 EC (pendimethalin), Ronstar 25 EC (Oxadiazon), Treflan 5 EC (trifluralin), Acetor 50 EC (acetochlor) and Dualgold 960 EC (S-metolachlor) was evaluated along with hand weeding and weedy check. The herbicides studied for weed control and their effect on seed cotton yield and its components during 1999, 2000 and 2001.The recommended production technology except herbicidal treatments was adopted for all the experiments. Most dominant weeds were Echinochloa colonum), Cyperus rotundus, Covolvulus arvensis), Digitaria sanguinalis and Cynodon dactylon. The data were recorded on phytotoxicity of herbicides on the crop, weed mortality and weed density, bolls per plant, boll weight and seed cotton yield. Non of the herbicidal treatments showed phytotoxicity on the crop except Dualgold 960 EC which adversely affected the crop germination and plant population when it was incorporated in soil. Results further revealed that in all the treatments, hand weeding and chemical weed control treatments were at par in reducing the weed infestation and increasing the seed cotton yield.