Rotavirus and Escherichia coli are the most common causes of scours, rotavirus alone accounts for about 27- 36% of calf scours incidence worldwide. A total of 65 fecal samples were randomly collected from diarrheic calves up 5 weeks of age in different localities in El- Wady El-Gedid governorate. All fecal samples were examined to determine the presence
of bovine rotavirus (BRV) and E. coli, as causes of calf diarrhea. Twelve (18.46%) and 18 (27.69%) out of 65 fecal samples were positive to rotavirus using Lateral flow and ELISA testes respectively. The infection rate of E. coli was (46.15%).The Age with higher incidence of Rotavirus infection was recorded in 8-15 days of age (with percentage of 12.31%), but
higher incidence of E. coli infection was recorded in 1-7 days of age (with percentage of 16.92%), and incidence of co-infection was (10.77%). Results also revealed that the infectious rate of BRV, E. coli and co-infection were higher in winter with percentages of 18.46 %, 24.62 % , and 7.69 % than autumn (7.69%, 12.31% and 3.08% ).In spring the infections
were 1,53%, 6.15 % and zero % while in summer the rates were zero %, 3.08 % and zero % respectively. Serotyping of E. coli revealed the presence of O142, O55, O111, O27, O157, O119, O26 and O127 by a percentage of 26.67%, 20%, 13.3%, 10%, 6.6%, 3.3%, 6.6% and 6.6%, respectively. Multiplex PCR was applied for detection of the virulence genes stx1 (5/10), stx2
(3/10) and eae (6/10) in E.coli isolates