The study was conducted to assess the importance of the Cestrum aurentiacum in maintaining the avian diversity of the Nilgiris. The study was conducted from December to March in five different sample sites located at Ooty, the Nilgiris. The avian diversity was calculated by counting the number of birds in one hour. The experiment was repeated many times and the mean number/hr is calculated. The site selection was done as per the standard sampling ecological protocols. The composition of inflorescence, the column diameter of the flower, the nectar height also were studied and correlated to the avian diversity. The avian diversity was assessed by calculating the Shannon Index and Simpson’s Index. Results shows that in the inflorescence there is a good number of mature flowers along with bud and the mature flowers contain plentiful quantity of nectar. Not only the birds, insects and other fauna were also attracted towards the Cestrum flowers. The Cestrum bushes are good nesting places and there are only minimum human disturbances. To be concluded, these reasons attract diverse faunal component to the Cestrum bushes. The study suggests that the exotic plant Cestrum bushes are becoming an unavoidable part of the Nilgiris supporting rich faunal diversity.