The current study aimed to detect microbial causes of she camel's subclinical and clinical mastitis and antibiotic sensitivity test for some bacterial isolates. A total of 196 milk samples were collected from mastitic and apparent healthy she camels, milk samples of apparent healthy she camels were examined by California mastitis test for detection of subclinical mastitis. All samples were cultivated on different media for detection of bacteria and fungi causing mastitis. S. aureus and Acholeplasma were subjected to antibiotic sensitivity test to detect antibiotic of choice. Out of 40 apparently healthy she camels, subclinical mastitis was detected in 19 (47.5%). Out of 196 she camels milk samples, 40 samples were positive for bacterial isolation (20.4%). E. coli and Staphylococcus epidermidis were the most predominant isolated bacteria from apparently healthy she camel milk samples while Pseudomonas aeruginosa, Staphylococcus epidermidis and Streptococcus agalactia from mastitic she camel's milk samples. This is the first record for isolation of Acholeplasma laidlawii in South Sinai where 4 Acholeplasma laidlawii isolates were isolated from mastitic and apparent healthy she camel milk samples. Aspergillus niger was the most predominant fungi followed by Candida albicans. The most predominant mixed bacterial infection in apparent healthy she camels was Proteus vulgaris and Staphylococcus epidermidis while from mastitic she camels was Pseudomonas aeruginosa and Klebsiella pneumoniae. S. 308 Marwa E. Abo Hashem et al. aureus was sensitive to gentamycin, streptomycin, erythromycin, tetracycline, ciprofloxacin and nitrofurantion. Acholeplasma laidlawii was sensitive to gentamycin. From the obtained results, it was concluded that she camels' mastitis was caused by several bacteria and fungi either by single or mixed infection.