D ICROCELIOSIS is a prevalent parasitic disease in ruminants and in humans and is accidental caused by different species of Dicrocoelium spp. This study aimed to evaluate the morphological characteristics and molecular parameters of Dicrocoelium spp. isolated from livers of slaughtered sheep, goat, and cattle in three provinces in west of Iran from Feb 2018 to Feb 2019. In the present study, 45 infected livers with Dicrocoelium were collected (each province 15 and each host 5 infected liver). After morphological examination, the molecular evaluation was carried out for the ribosomal DNA (partial 5.8S, complete ITS2 and partial 28S genes) using PCR and PCR-RFLP techniques. Morphological analysis revealed that all specimens belonged to Dicrocoelium dendriticum. There were profound morphometric variations among D. dendriticum from different hosts and sampling areas, but no statistically significant differences was found (P>0.001). The sequencing analysis of obtained fragments in GeneBank showed 96% to 100% similarity within homogeneous fragments in the database. The obtained sequences were also registered in Gene Bank with the accession numbers, MN831473, MN831474 and MN831475. Additionally, all PCR-RFLP products revealed two similar fragments (319bp and 271 bp) in all examined samples. According to the present study, haplotype A was shown to be the predominant haplotype of D. dendriticum in the west of Iran.