Objectives: The aim of this study was to evaluate, by the semi-quantitative histological analysis, the anti-inflammatory activity of the ethanolic extracts of Serjania erecta e Zeyheria Montana, in experimental pulpits in rats. Study Design: In order to induce pulp inflammation, cavities were performed on the occlusal surface of the mandibular first molars of 45 male rats, without pulp exposure. The animals were distributed into 4 groups: GI, teeth without cavities; GII, single dose of saline solution via intraperitoneal (IP); GIII, single dose (IP) of 300mg/Kg of ethanolic extract of Zeyheria montana; GIV, single dose (IP) of 300mg/Kg of ethanolic extract of Serjania erecta. After 6, 12 and 24 hours, 5 animals of each group were killed by anesthetic overdose. The histological analyses of the pulp tissue were performed and the data analyzed by Dunn´s multiple test, at significance of 5%. Results: After 12 h, the GIII presented score statistically lower (p<0.05) than positive control group. After 24 h, GIII presented inflammatory index statistically lower than the positive control (p<0.01) and Serjania erecta (p<0.05) groups. Conclusion: The Zeyheria montana extract presented better anti-inflammatory activity than positive control group and Serjania erecta extract, which did not show anti-inflammatory effect in the analyzed periods. Key words:Anti-inflammatory effect, experimental pulpitis, histological analysis, phytotherapy, rats.