Calotropis procera (Asclepiadaceae) is an erect, perennial shrub luxuriantly thriving in wastelands. It is commonly distributed in most parts of India and also distributed in Persia, tropical Africa and other tropical countries of the World. The aqueous extract of some parts have laxative property and beneficial in skin diseases, ulcers, enlargement of the spleen, abdominal glands, liver diseases, promotes digestive power and also useful in colics. The milky exudate is useful in skin diseases, tumour and ascitis. It is a very good purgative. Here an attempt has been taken to evaluate the antioxidant activity, CNS depressant activity and also antimicrobial activity of methanolic extract of fresh flowers of C. procera. In result, the methanolic flower extract showed a significant activity against DPPH free radicals and the IC 50 value is 64.87µg/ml. On the other hand, CNS depressant activity of the extract was also observed by using In Vivo model. In antimicrobial activity five different fungal species were inhibited by this extract and from the above study the flowers extract showed the maximum zone of inhibition against Candida parapsiliasis and the minimum against P. notatum ATCC 11625. Simultaneously, four different bacteria were inhibited in the concentration of 1mg/ml up to 4mg/ml flower extract of C. procera showing significant zone of inhibition against those.