Abstract The objective of the work was to conduct a biodiversity study on lactic acid bacteria (LAB) prevailing in the samples of house hold dahi and to evaluate the potency of the isolates to function as active starter cultures. Forty four isolates of LAB (IS-1 to IS-44) were identified from home-made dahi. Biochemical test results proved that isolates were of four different species viz ., Streptococcus thermophilus, Lactobacillus acidophilus, Pediococcus acidilactici and Lactococcus lactis . On comparison of culture activity between different groups of LAB isolates, significantly higher (F<0.01) acid production was observed in group II ( L. acidophilus ) and group IV isolates ( L.lactis ), proving that these two groups of isolates were good starters. With respect to MBRT, group II ( L. acidophilus ) and group III ( P. acidilactici) isolates showed a significantly low dye reduction time proving that they were better starters. Tyrosine value of isolates belonging to group I ( S. thermophilus ) and group II ( L. acidophilus ) were significantly higher. Of the 44 isolates tested 34 percent of the isolates showed the reduction time less than 35 min. proving that all these isolates were “excellent” in their starter activity and ninety percent of the screened LAB isolates showed tyrosine value above 0.2 mg/ml. confirming that most of the selected isolates were having good proteolysis ability. In this study L. acidophilus showed better acid production, proteolytic ability and fast dye reduction. Since the performance of a starter culture is greatly dependant on their activity and purity, it was established that group II isolates was the excellent among screened samples. This study also revealed that the wild strains of LAB existing in home-made dahi are potential source of commercial starter cultures.