Diarrhea is the most important disease in neonatal dairy and beef calves. Significant economic loss occurs due to increased morbidity and mortality, treatment costs and reduced growth rates. Rotaviruses usually cause diarrhea during the first three weeks of life. Clinical signs can be quite variable and are similar to those caused by other neonatal bovine enteropathogens such as corona virus and Eschericia coli. Diagnosis of rotavirus in calves is based on the identification of viral particles, antigens or nucleic acids in feces. Tests include direct or immune electron microscopy, immunofluorescence, antigen capture enzyme- linked immunosorbant assay (ELISA), latex agglutination and polymerase chain reaction (RT-PCR). All of these tests are useful for diagnosing rotavirus infections, but in general are relegated to use by diagnostic laboratories. Development of an on-site diagnostic assay for bovine rota virus would be a useful tool for veterinarians and cattle producers in making management decisions regarding neonatal bovine diarrhea. The ImmunoCardSTAT Rotavirus (ICS-RV) Assay (Meridian Diagnostics, Cincinnati, OH) is a patient-side assay designed to detect group A rotavirus in humans. This assay is based upon rapid immunomigration (RIM) technology. This technology allows for packaging of all reagents into a single-step assay that can then be used patient-side (similar to a "home pregnancy test"). The objective of this study was to evaluate the ICS-RV assay's usefulness as an on-site diagnostic test for bovine rotavirus.