Nyctanthes arbortristis Linn. (Oleaceae) is one of the well-known Indian medicinal plant. Various extracts of leaves of the plant were screened for analgesic activity by hot plate test and acetic acid-induced writhings and anti-inflammatory activity by carrageenan-induced hind paw edema method at the dose of 50 mg/kg, i.p. Petroleum ether extract was found to be most active and hence subjected to activity-guided fractionation. Results showed that β-sitosterol (5, 10 and 20 mg/kg, i.p.) was responsible for the significant and dose-dependent activity comparable with the standard extract. β-Sitosterol from N. arbortristis leaves might be responsible for analgesic and anti-inflammatory activity.