Abstract: In this study, the prevalence of Bovine rotavirus (BRV) and Bovine Corona Virus (BCV) infections were investigated in blood serum of 498 unvaccinated adult cattle in northeast part of Turkey by using the virus neutralization test. The results showed that seroprevalence of BRV was found in 146 (29.3%) and that of BCV was found in 131 (26.3%) in tested cattle sera. Antibodies to both viruses were found in 21 (4.2 %) cattle sera. From the results, it can be assumed that BRV and BCV infections are common among the adult cattle and the seropositive animals should be considered as a source of infection within the herd.