Field investigations carried out in two winter seasons of 1984–85 and 1985–86 on clay‐loam soil at the Central Institute of Medicinal and Aromatic Plants, Regional Centre, Pantnagar, Naintial, India revealed that unrestricted weed growth reduced the seed and oil yields of Bulgarian coriander(Coriandrum sativumL. cv. S 33) by 40.3 and 37.0%, respectively. Applications of pendimethalin and fluchloralin at 0.75 and 1.00 kg a.i./ha, respectively causing 76.5 and 71.9% weed control, were most promising treatments, and gave seed and oil yields comparable to weed‐free check. Applications of oxadiazon at 0.25–0.75 kg a.i./ha and propanil at 1–2 kg a.i./ ha, although proved selective but failed to produce desired results. None of the treatments impaired the quality of coriander seed oil, measured in terms of d‐linalool content.