This research was conducted for determine scientifically the anti-inflammatory property attributed popularly to the plant Ageratina sternbergiana (DC.) RM King & H. Rob ``Zun Zun´´, used for inflammation. The Antiinflammatory activity was evaluated by subplantar edema method according to Winter et . al. The method consist to cause inflammation in the left hind paw of the experimental animals, which can be reduced by the anti-inflammatory substances. We used 18 albino mice (male and female) strain Balb C53 in 6 groups: control (no treatment), 3 groups with ethanol extract of stems at doses of 50 mg / kg, 100 mg / kg, 200 mg / kg and 1 group hydrolyzed ethanol extract of stems at doses of 160 mg / kg and 1 group with indomethacin in doses of 10 mg / kg. The application of all treatments were oral. The pharmacological results indicate that treatment with ethanol extract of the stems o...