Rotaviruses were detected by an ELISA test in stool specimens from diarrheic rabbits in two commercial rabbitries and cultured in MA 104 cells. Their identity was confirmed by electron microscopy and indirect immunofluorescence. They were found to belong to subgroup I by testing with monoclonal antibodies and to serotype 3 by neutralization with homologous and heterologous antisera. Although both viruses were neutralized by antiserum to human serotype 3 the ALA rabbit rotavirus was minimally neutralized by antiserum to the C11 rabbit rotavirus. Electrophoresis of viral RNA revealed 11 segments characteristic of rotavirus, however both rabbit rotaviruses had unusual electropherotypes. They differed from each other with greatly reduced mobility of the tenth segment in one virus and the eleventh segment in the other virus.