Background: Antioxidants play a major role in curing degenerative disease. In present time many synthetic antioxidants are commonly used but due to their toxic and carcinogenic effects, their use has been restricted. So the search for natural antioxidants is important. Studies on natural compounds is of interest due to their satisfactory health benefits with low toxicity. Objective: The antioxidant activity of ethanol and aqueous extract of shoot, seed and leaf of an important medicinal tree Nyctanthes arbor-trist is (Harsingar) were evaluated by DPPH scavenging antioxidant assays. Materials and Methods: Different concentrations 25, 50, 75, 100% of the aqueous and ethanol extracts were prepared with standard solutions (ascorbic acid 0.01, 0.03, 0.05, 0.07, 0.09, 0.1 mg/ml). To 1.5 ml solution of DPPH (0.1 mM), 0.5 ml of various concentrations of the extract and standard were added. Results: In the present study a comparative evaluation of antioxidant activity of seed, shoot and leaf of Nyctanthes arbor-tristis Linn was performed for their aqueous and ethanol extracts. Ethanol and aqueous extracts of shoot revealed more antioxidant activity then seed and leaf. Conclusion: All aerial parts of Nyctanthes arbor-tristis Linn possess antioxidant activity. The plant may be functioned out for its anticancerous properties in future.