Abstract - Mastitis is one of the major diseases affecting lactating animals. The objectives of this study were to determine the prevalence of subclinical mastitis in cows by California mastitis test (CMT) and to compare the CMT results with somatic cell count (SCC) in selected areas of Satkhira district in Bangladesh. A total of 151 cows and 604 quarters of mammary glands derived from 68 small and medium farms were examined by CMT. To compare the CMT results with SCC, somatic cells in the same milk samples of 297 quarters were examined by the Nucleo Counter SCC-100 machine. The CMT results showed that 42.4% of examined cows were positive where one or more quarters had subclinical mastitis. Moreover, 16.2% of tested quarters had subclinical mastitis as diagnosed by CMT. When SCC was done, median values of CMT negative, trace, moderate, distinct and strong CMT score were 84000, 559000, 1203000, 1850000 and 1755000 per ml of milk, respectively. The SCC had a strong positive correlation with the CMT score (r=0.9602). The sensitivity, specificity and accuracy of CMT compared with SCC were 40.7, 96.7 and 69.4%, respectively. Results indicate that both CMT and SCC can be used as tools for the diagnosis of subclinical mastitis in cows.