Background: Yangambin, a lignan isolated from Ocotea duckei leaves, has been reported to have antitumor, anxiolytic, hypotensive, and leishmanicidal activity, but there is little information on toxicity. Objective: The aim of this study was to investigate the acute toxicity of yangambin in mice, and cytotoxicity and genotoxicity through the Allium cepa assay. Materials and Methods: The yanganbin at a dose of 2000 mg/kg was orally administered once to mice to investigate acute toxicity, and meristem of the roots of Allium cepa was used to determine inhibition of root growth (root length) and mitotic index. Results: Yangambin did not cause hemolysis in sheep erythrocytes at concentrations of 12.5, 25, and 50 µg/mL, and did not show genotoxic changes in root meristem cells of Allium cepa at the same concentrations. In the acute toxicity study in Swiss mice at a dose of 2000 mg/kg, there were no apparent clinical signs or any behavioral changes and no deaths. Conclusion: Therefore, yangambin appears to a promising active compound for future pharmacological studies.