This study was undertaken to investigate the effectiveness of California mastitis test (CMT), white side test (WST), chlorine test and electrical conductivity (EC) in the diagnosis of subclinical mastitis in dairy cows in a comparison to somatic cell count (SCC) as a standard method for detection of subclinical mastitis. One hundred random samples of cow’s milk were collected from different dairy farms at Dakahlia Governorate, Egypt. SCC revealed that 27% of samples contained less than 2×105 SCC/ml. and were considered negative for presence of subclinical mastitis, while mastitic samples (73%) contained higher numbers of SCC exceeded 2×105/ml. CMT results revealed that 27.0% of the examined cow’s milk samples were negative and 73.0% were among the positive samples. The mean values of chlorine % of normal and mastitic cow’s milk samples were 0.093 and 0.157, respectively. EC of normal and mastitic cow’s milk samples revealed that the mean values were 4.08 and 7.42 mS/cm, respectively. Results showed significant correlation of these parameters in detection of subclinical mastitis milk samples.