A rapid and simple technique for diagnosis of rotaviral diarrhea is polyacrylamide gel electrophoresis (PAGE) of dsRNA extracted from fecal samples. To determine the electrophoretype of Iranian calf rotavirus, 23 rotaviral positive fecal samples from diarrheic Holstein calves at the age of less than one month in Tehran region were examined. The viral dsRNA was extracted with phenol-chloroform, and analyzed by PAGE and silver staining. According to PAGE all of the electrophoretypes were identified as long genome electrophoretypes, characteristic of animal group A rotavirus. There was not any unusual segment rearrangement.