Background and Aim:Bovine mastitis is one of the most costly and prevalent diseases in dairy herds, which can be prevented and controlled through proper milking practices, diagnosis, and elimination of chronic animals, among others. Contagious pathogens such asStaphylococcus aureusand environmental pathogens such asEscherichia coliandKlebsiellaspp. can affect cows and milk for human consumption, generating a public health risk. This study aimed to estimate the prevalence of herds with somatic cell count (SCC) ≥200,000 cells/mL,S. aureus,E. coli, andKlebsiellaspp., in bulk tank milk (BTM) and its associated risk factors in Colombian dairy cow herds.Materials and Methods:A cross-sectional probabilistic study was carried out in 150 dairy herds located in the north of the Antioquia province. A single visit per herd was conducted, during which three BTM samples were aseptically collected. General data and milking practices were collected through an epidemiological survey applied in each herd.Results:The prevalence ofS. aureus,E. coli, andKlebsiellaspp. were 14% (21/150), 2% (3/150), and 8% (12/150), respectively. Moreover, 95% of the herds presented an SCC of ≥200,000 cells/mL. Practices such as in-paddock milking, change of milker during the last month, use of disposable gloves, and hand disinfection were associated with increased prevalence ofS. aureus, whereas proper dipping was a protective factor. Proper washing and disinfection of the milking machine, use of chlorinated disinfectants for hand hygiene, and use of disposable gloves decreased the prevalence ofE. coliandKlebsiellaspp. Bulk tank SCC increased in herds with 30–60 milking cows, herds with >60 milking cows, and herds with a change of milker during the last month. Hand disinfection and dipping decreased the SCC.Conclusion:Staphylococcus aureus,E. coli, andKlebsiellaspp. were prevalent in BTM from dairy cow herds. The risk ofS. aureusisolation was higher in herds with an in-paddock milking system. The risk ofE. coliandKlebsiellaspp. isolation were higher in herds with >60 milking cows, with a change of milker during the last month. Processes such as avoiding changing the milker and greater control in medium and large herds could improve the SCC in BTM.