Sub-clinical mastitis, a highly prevalent chronic disease of crossbred cows in Orissa, reduces milk production to the extent of 10 to 20 % and also significantly decreases the quality of milk by influencing the fat, protein and carbohydrate concentration of milk. Both the microorganisms and toxins produced by microorganisms in subclinical mastitis milk affects the human health. The economic loss due to subclinical mastitis has been estimated up to 40%. The diseases is considered to be highly dangerous as it has no outward clinical manifestation and difficult to diagnose at early stage with the presently known diagnostic methods. Hence it has been attempted to diagnose the subclinical mastitis and assess the milk quality by somatic cell counts (SCC) and correlate the SCC with microbial load of mammary gland for prognosis. The milk samples from 400 quarters of 100 crossbred Jersey cows (2^nd lactation) of small herd dairy units in and around Bhubaneswar preliminarily screened for subclinical mastitis by Modified Californian Mastitis Test. The preliminary screening of milk samples revealed that about 41 % of the quarters were positive for subcliniacal mastitis. The total microbial load (× 105 CFU/ml) of the subclinical mastitis milk (21.94±0.38) was significantly (P<0.01) higher than the unaffected cows (1.85±0.02). Bacteria like Staphylococcus aureus, Streptococcus agalatiae, Bacillus spp., Alcaligen spp. and Pseudomonas spp. were found to be predominant.