The genus Baccharis, Compositae family, known popularly in Brazil as "carqueja", is a woody perennial shrub, 0.5-4.0 m in height, widely used in the South American folk medicine to treat gastrointestinal and liver diseases, angina, poor blood circulation, diabetes and inflammatory processes. The aim of this study was to analyze the effect of ethanolic extract of Baccharis trimera (EEBt) on macrophage activity, once these resident cells made the first sign to activate neutrophils migrate to the inflammatory site. A voucher (HB 86447) specimen of Baccharis trimera was deposited at Bradeanum Herbarium (UERJ). The ethanolic extract was obtained by maceration of the whole plant (1 g/50 mL) on ethanol 80% during 7 days. The extract was evaporated under reduced pressure yielding 9%.  The recruitment of leukocytes was evaluated on air pouch model. Five and three mL sterile air was inflated on day 0 and 3 (respectively) in the dorsal skin. On day 6, animals received the EEBt, dexamethasone (0.5 mg/kg b.w.) or the vehicle (ethanol 15% with 1.25% Tween-20) i.p. and, after 1h was administrated carrageenan 1% into the air pouch. After 4 hour, the exsudate was harvested with NaCl 0.9% (1 mL) containing EDTA 2 mM. Aiming  to analyze the activity on macrophage cells, RAW 264.7 cells were cultured in medium DMEM in 96 well plate (100 x 10⁵/well). The cells were treated with different concentration of EEBt (2h) and activated with LPS (1 mg/mL overnight) so as to induce nitric oxide (NO) production. The supernatant was removed and added to Griess reagent and the cells were treated with MTT salt solution (5 mg/mL). Both reactions were analyzed in microplate reader at 550 nm (NO production) and 570 nm (tetrazolium salt reduction). The treatment with 3 and 30 mg/ kg b.w doses showed a significant (p<0.5) anti-inflammatory activity (Tukey's Test) inhibiting the cell migration in 27 and 50% respectively, as much as the dexamethasone treatment (44%). Only the concentrations among 10 and 100 mg/mL inhibited the production of NO (12 and 95%, p<0.5 and p<0.001, respectively), but the reduction was related with inhibition of cell viability (39 and 52%, p<0.5 and p<0.001, respectively).This date suggest that EEBt perhaps has no effect on macrophage activity. Supported By: UERJ, FAPERJ.