SUMMARY
 
In a survey on Heamonchus infection in sheep at Assiut Governorate, the overall infection rate was 18% out of 150 living animals that diagnosed by faecal samples examination and 49.06 % out of 53 slaughtered sheep that diagnosed by abomusum examination. In adult sheep the infection rate was 30 %, while Heamonchus eggs were not detected in lambs. Two species of Heamonchus were detected in the present work: H. contortus and H. placei. The morphological characters of each species were described. The second part of the present study was carried out to evaluate in-vitro the anthelmintic effect of different extracts of Ferula hermonis. The obtained results showed that all extracts of F. hermonis have variable degree of anthelmintic action against both adult worms of Haemonchus and their 3^rd stage larvae in- vitro. Ethyl acetate extract of  F. hermonis at 5 mg / ml and 2.5 mg / ml has the greatest inhibitory action against both adult worms and 3^rd stage larvae of Haemonchus. Our present investigation is the first study to evaluate the anthelmintic activity of different extracts of Ferula hermonis against Haemonchus.