The present study was conducted to evaluate the analgesic activity of ethanolic extract ofAndrographis paniculata (AP) in mice. The analgesic investigations were carried out using theacetic acid-induced abdominal writhing and the hot-plate tests. It was demonstrated thatintraperitoneal (i.p.) administration of the extract at a dose of 30, 100, 300, 500 mg/kg, producedsignificant inhibition of abdominal constriction induced with 0.6% (v/v) acetic acid in dose-dependent manner. It also demonstrated that the extract produced significant dose-dependentincrease in the time of latency to a discomfort reaction in the hot-plate model. In addition, theanalgesic effect of the ethanolic extract of AP was significantly reversed by a non-specific opioidreceptor antagonist, naloxone. These results indicate that AP has an analgesic effect that wasmediated through opioid receptors.