Pathogenic E. coli strains of gastrointestinal infections are significant cause of diarrhea in both children and calves worldwide, especially in developing countries.The aim of this study was to identify pathogenic E.coli strains and study their antibiotic resistant patterns to commonly used antimicrobials agents isolated from diarrheic children younger than five and in contact calves. The study was conducted in Hospitals including Injibara General Hospital and two primary Hospitals (Dangila and Agew Gimjabet). Purposive sampling was used to collect 107 stools and 50 o fecal samples from all study sites. E.coli isolates were identified based on their appearance pink colonies on MacConkey agar, green metallic sheen appearance on EMB and colonies were identified through IMViC (+ + - -) biochemical tests. Genomic DNA was extracted from the isolates for strain identification using PCR. Then, positive PCR isolates were subjected to antibiotic susceptibility profile testing and carried out using agar disc diffusion method on Muller Hinton agar following standard procedures. A total of 79/107(73.8%) isolates were found to be positive for E.coli in children with diarrhea. The distribution of E.coli in age category of 25-60month is more infected with E.coli infection than other age groups. Out of 79 isolates, 39(49.4%) carry one or more virulence genes. So, 26.6% for ETEC, 6.3% aEPEC, 5.1% EAEC, 3.8% STEC, 3.8% EHEC and 3.9% atypical pathotypes were detected. In addition, 38/50(76.0%) out of the 50 incontact diarrheic calves were positive for E.coli.The frequency of E.coli infection were more in cross breeds than local breeds. After thirty-eight samples were processed using PCR, 29 (76.3%) harbored one or more virulent genes which includes the following pathotypes; 7(18.4%) EPEC with atypical, 13.2% for ETEC where, EHEC and STEC constituted 7.9% each. Also, mixed pathotypes were also identified and comprised of 28.9%. Most isolates from children and calves were sensitive to norfloxacine and tetracycline and were resistant to streptomycin and gentamicin. Escherichia coli isolates, 33(84.6%) from diarrheic children and 17(58.6%) from isolates of diarrheic calves were resistant to two or more antibiotics. The study concludes E.coli strains of STEC, EHEC, aEPEC, and mixed pathotypes detected in common from diarrheic children and in contact diarrheic calves implies calves are major transmitter and reservoir pathogenic strains of E.coli to humans. Therefore, possibility of contact children with calves in home should be avoided and awareness to parents or caretakers of children on exposing E.coli should also be created.