is a lethal protozoan disease, responsible for the loss of livestock in Iran and in the world. The purpose of the current study was to detect and identify spp. infection using microscopic and molecular methods in human, sheep and goats in Kuhdasht region, in the Lorestan Province, west of Iran. During 2013, a total of 384 blood smear samples were collected from 51 goats, 306 sheep suspected of infection and 27 humans from Kuhdasht region. The blood samples were fixed, stained and under light microscopic examined. DNA samples were extracted and amplified by polymerase chain reaction of 18S-rRNA gene. PCR and the semi-nested PCR were performed to identify to and to differentiate genus of and spp. The results of microscopic examination indicated that a total of 47 (12.2%) samples were positive for spp. infection: 38 (9.9%) belonging to sheep and 9 to goats (2.3%). No was observed in human samples. The PCR showed a band size of 389 bp, of spp. and the semi-nested PCR detected with a band size of 186 bp. By molecular method, 16 (4.2%) sheep and 2 (0.5%) goat blood samples were infected by. Totally, 18 samples (4.7%) were observed to have a, while no infection was found in human. Thus, the results of our study have shown sheep and goats could be vulnerable to spp., especially in Lorestan Province, Iran. Therefore, studies on the status of the animal especially are recommended.