Subclinical mastitis is an insidious disease of the mammary gland that negatively impacts the production of dairy cows. The objective of the present study is to screen subclinical mastitis in dairy cattle farms. A total of 208 lactating cows from five herds were examined and screened by the California mastitis test (CMT). Bacteriological analysis was performed on all CMF positive milk samples to characterize the presence of infection due to the genus Staphylococcus; as well as studying of the sensitivity of these isolated strains to antibiotics. The results showed that out of 208 cows screened by CMT, 71.15% were positive. Bacteriological analysis revealed that 111 samples found to be of the genus Staphylococcus, (75%). The characterization of the strains affirmed that the coagulase positive staphylococci represent 51.34% with a predominance of Staphylococcus aureus with a rate of 40.54% and the coagulase negative staphylococci represent 48.61%. The results of the antibiotic resistance revealed that the strains of coagulase positive Staphylococci particularly S aureus are resistant to the combination of amoxicillin and clavulanic acid, oxacillin and tetracycline with levels ranging from 4.4%, 44, 4% and 11.1% respectively. While coagulase negative Staphylococci showed resistance to the same molecules with 9.2%, 16.6% and 31.3% respectively. The obtained results demonstrated a very strong correlation between CMT and bacteriological findings. CMT seems to be an advantageous tool to expand, for systematic and regular screening against subclinical mastitis.