Distribution of hemorrhagic septicemia (VHS) by molecular method (RT-PCR) in rainbow trout breeding centers in Chaharmahal and Bakhtiari province were studied in 2015. As for the possibility of synchronously involvement of farms with viral diseases of hematopoietic necrosis (IHN), pancreatic necrosis (IPN) and hemorrhagic septicemia (VHS) with similar clinical symptoms, from 169 trout breeding centers ¬ Rainbow disease and high mortality were sampled. The results showed that the relative frequency of disease (VHS) was 11.83%, of which Kiar city with 17.7% had the highest and Koohrang city with 9.67% had the lowest infection. The average prevalence of disease (IPN) was 24.85% and disease (IHN) was 16.56. Also, the prevalence of diseases (VHS) and (IHN) in river water sources was higher than in other water sources.