The dried aqueous extract of Trichilia roka Chiov. (Meliaceae) root was evaluated for its potential antipyretic activity on yeast-induced hyperthermia in rats. The drug showed a significant reduction of body temperature when administered orally at the doses of 0.25, 0.5 and 1.0 g/kg. The antipyretic activity of T. roka was compared to indomethacin treatment (50 mg/kg), used as a reference drug. The results of this study confirm the validity of traditional usage of T. roka as an antipyretic agent. Moreover, micromorphological investigations were carried out by scanning electron microscopy obtaining useful phytognostic elements for the correct identification of the drugs both in scraped and powdered forms because this is of great interest for quality control in basic research and drug production, especially for imported items and for raw material sold by traditional herborists.