A total of 50 fecal samples of diarrheic buffalo calves aged 0–3 months collected from private farms in Giza Governorate, were examined for detection of the most common bacterial pathogens causing diarrhea. The results revealed that, 24 samples (48 %) were positive for Escherichia coli, 7 (14%) for Salmonella Typhimurium; 6 (12 %) for Staphylococcus aureus, 5 (10 %) for Streptococcus faecalis; 5 (10%) for Pseudomonas aeruginosa, 3 (6%) for Klebsiella pneumoniae and 2 (4%) for Proteus vulgaris. Serological diagnosis showed that, 16 strains belonging to five O-serogroups which included O111 (5 strains), O26 (4 strains), O125 (4 strains), O103 (2 strains) and O157 (1 strain). With respect to Candida spp. participate 60% of the total yeast isolated from diarrheic calves. C. albicans was the most frequently recovered spp. (22%) followed by C. glabrata (16%), Candida krusei (10%), C. guilliermondii (4%) and Rhodotorula spp. (8%). Antibiotic sensitivity test proved that, E. coli isolates showed resistances against the majority of antimicrobials, it showed high resistances against amoxicillin followed by ampicillin erythromycin, cefotaxime and trimethoprim sulfamethoxazole. On contrary, isolates were showed high sensitivities against levofloxacin and ciprofloxacin followed by gentamicin, neomycin and colistin sulfate. On the other hand, S. Typhimurium showed high resistance against ampicillin followed by amoxicillin, erythromycin and trimethoprim-sulfamethoxazole, while isolates were showed high sensitivities against levofloxacin and ciprofloxacin followed by colistin sulfate, gentamicin, Cefotaxime and neomycin. Currently, sensitivity to commercial antifungal against C. albicans indicated that, it was highly resistant for fluconazole followed by ketoconazole and clotrimazole, while, it was completely susceptible to nystatin followed by amphotericin B.