Solidago chilensis Meyen, belonging to the family Asteraceae, is a plant native to South America and the only representative of the genus in Brazil. This species is popularly known as "arnica" and is used to treat bruises, muscle pain and inflammation. The objective of this work was to contribute to the pharmacognostic standardization of S. chilensis. Cross-sections were obtained, by freehand, for microscopic analysis of root, stem and leaf; for these parts of the plant maceration was also performed according to the method of Jeffrey. For the leaf were still made paradermal sections, scanning electron microscopy analysis, phytochemical and histochemical tests. Thus, it was determined anatomical features useful for diagnosis of the species which, together with identification of the chemical compounds and its histolocalization, provides support to their quality control.