BackgroundSubclinical mastitis remains a major challenge in the dairy industries as it affects nutritional content of milk and milk products, volume of milk production and also leads to economic loss. This study was carried out to determine the relationship between California Mastitis Test (CMT) scores and bacteria counts in the diagnosis of subclinical mastitis. A total of 339 white Fulani cattle milk samples were aseptically collected from six geographical regions of Plateau State and screened for mastitis and bacteriological analysis using the California Mastitis Test (CMT), Total Bacterial Count (TBC) and Total Coliform Count (TCC) methods respectively. ResultsThe result of the study reveals that 31.0% of the milk samples were positive for mastitis. Based on the CMT scores, 61.9% of the samples were CMT negative, 7.1% were CMT trace while 6.5%, 11.5% and 13.0% were CMT +, CMT ++ and CMT +++ respectively. Most of the CMT negative samples (55.71%) were culture negative while almost all the CMT +++, were positive (90.91%) culture positive. A positive correlation was observed between CMT scores and plate counts (Total Bacteria count and Total Coliform Count). The Total Bacteria count ranged from 5.7x101 – 5.9x106 CFU/mL while the Total Coliform Count ranged from 0.6x101 – 3.0x105.CMT scores correlates well with bacteriological plate count of the mastitic milk samples. ConclusionThere is a need for the improvement in quality and safety of dairy product because of public health risk associated with it