The reduction of Haemonchus contortus (L3) infective larvae in sheep faecal cultures caused by the action of three nematophagous fungi conidia was evaluated in vitro. Addition of 20,000 conidia of Monacrosporium eudermatum, Arthrobotrys oligospora and Arthrobotrys robusta per gram of faeces caused a reduction of 95.7%, 98.3% and 10.1%, respectively, compared with the control group. A 97.4% reduction was observed when combined conidia of the three fungi were used. Total reduction of the larval population was observed by addition of the three fungi at 100,000 conidia per gram of faeces.