Abstract Field experiments were conducted on a heavy clay soil of Central Sudan to study the effectiveness of some pre‐planting and pre‐emergence herbicides on kenaf, Hibiscus cannabinus L. Pre‐planting application of trifluralin at 1.2 to 2.4 kg/ha and pendimethalin at 1.2 to 2.4 kg/ha were found to be the most promising herbicides for weed control; nitralin at 1.2 kg/ha was less effective, while EPTC at 3.6 kg/ha caused crop damage with significant reduction in yield. Among the pre‐emergence herbicides fluorodifen at 3.6 to 4.8 kg/ha and pendimethalin at 1.2 to 2.4 kg/ha were the best. Oxadiazon and its tank mix with diuron were considered to be too damaging for recommendation to growers.