75 Misti dahi samples from different districts of West Bengal were collected randomly and analysed for physico-chemical, microbiological quality and antioxidant activity. Significant variations in the composition of the dahi samples were observed. The average fat, protein, lactose, ash, total solid, pH and titratable acidity content of dahi samples were found to be 3.94±0.55%,3.7±0.032 %,4.39±0.035 %, 0.66± 0.012%,12.82±0.087 %,3.48±0.045 and 1.16±0.00 % lactic acid respectively. Hydroxy methyl furfural (HMF) value, Peroxide value (PV) and Tyrosine value (TV) of the market dahi samples were found to be 1.03±0.04604μmole/L, 0.344±0.009milli eq. /kg of fat and 0.276±0.008 mg of tyrosine/ml respectively and varied significantly. Baudouin test which is an indicator of adulteration of dahi with Vanaspati showed positive results for 48% of the samples. Average coliform and Yeast & Mould count were found to be 4.37±0.21 log cfu/g and 3.54±0.11 log cfu/g respectively. Antioxidant activity was measured by ABTS and DPPH method. All Misti dahi samples showed good antioxidant activity and varied significantly (p<0.05).