Haemonchus contortus is a trichostrongyle nematode parasite of sheep and goats, and worldwide is considered to be the most important parasite of these species. It has a similar lifecycle to other parasitic trichostrongyle gastrointestinal nematodes, but it has a markedly higher fecundity, a preference for higher temperatures and a short pasture development time, which makes it epidemiologically different. Similarly, because of its blood-feeding habit the disease produced is distinct from parasitic gastroenteritis. This article summarises the differences in biology and control of H. contortus to other gastrointestinal nematodes of sheep, and covers specific control measures such as the use of FAMACHA© scoring, use of closantel and nitroxynil, the H. contortus vaccine, the effect of copper oxide wire particles, and the potential for breeding haemonchosis-resistant sheep and other future developments in H. contortus control.