At the W/V concentration of Ocimum sanctum (Linn.) extract, a zone of inhibition of 22mm was obtained. This was the widest zone of inhitoin observed/among all the 10 different concentrations tested. Hence, the Minimum Inhibitory Concentrstion of cold ethanolic extract of Ocimum sanctum (Linn.) against clinically isolated Actiinobacillus actinomycetemcomitans was 6% W/V (Tabal/Fig-2). The zone of inhibition for positive control was 25%mm and no zone of inhibition was observed around the negative control (Tabel/Fig-3)