This study was conducted to determine the ultrasound features and echo mean values obtained through histogram analysis of ultrasonograms of udder and teat in twenty three (23) Holstein-Friesian x Sahiwal crossbreed cows, 3-8 years old, with different grades of mastitis as determined using California mastitis test (CMT). Based on the results of the CMT, the 23 cows were classified into three groups: a) no mastitis (negative CMT, 4 cows); b) subclinical mastitis (trace CMT, 8 cows); and c) clinical mastitis (1-3 CMT, 11 cows). Ultrasonography of the teats and udders showed that the sinus and cistern of cows with mastitis (CMT grades 2 and 3) were more echogenic than those without mastitis. Histogram analysis of the teat and udder ultrasonograms showed significantly higher echo mean values in cows with grades 2 and 3 in CMT than in other groups. The results suggest that diagnostic ultrasound can be utilized for diagnosis of clinical mastitis in dairy cows.