Equine piroplasmosis (EP) is a tick-borne disease caused by two hemoprotozoan parasites, Theileria equi and Babesia caballi, which occurs in pre acute, acute, sub-acute and chronic forms. This disease is one of challenges for international movement of horses. The aim of this study is to evaluate hematological parameters and clinical signs of EP in purebred Arabian horses of Ahvaz. After clinical examination, Jugular blood was collected from 59 purebred Arabian horses (14 diseased and 45 clinically healthy horses) and complete blood count was performed for samples. The disease agents were identified using microscopic examination and multiplex PCR. Only T. equi was identified in the obtained samples. Horses were divided the to three groups (control, infected, diseased) according to PCR and clinical examination results. Clinical signs and hematological changes were discussed for each group. EP caused anemia in diseased group, while the infected group showed no obvious difference from control group. Fever, icterus or pale mucous membranes were the most frequent clinical findings in diseased horses. Stress seems to have special role in intensification of EP signs in purebred Arabian horses of Ahvaz. This is the first PCR confirmation of T. equi in purebred Arabian horses of Ahvaz. Khuzestan province is one of ancient centers for raising horses in Iran, especially for Arabian horses. Today, horse raising has become an industry in this region and according to the importance of EP for horse raising industry and economic losses of this disease, it seems more focus should be made for EP concerning its prevention and treatment in Khuzestan province.