Hydroxychavicol (HC) is a phenolic compound of betel leaf (Piper betle). It has been reported to haveantifungal properties against dermatophytes including T. rubrum. The aim of this study was to identify theeffects of the HC against T. rubrum. Broth dilution method was used to determine the minimum inhibitoryconcentration (MIC) and minimum fungicidal concentration (MFC) of the HC. Microscopic study of thetreated fungus was done by transmission electron microscope (TEM). Cytotoxicity study using pre-adipocyte(3T3-L1) cell line was performed by means of MTT cell proliferation assay. The MIC and MFC results of theHC were both 0.49 μg/ml. Microscopic study revealed the destruction of the fungal cell wall and organelles.Cytotoxicity study showed HC to be non-toxic to the tested human cell line. In conclusion, HC maypotentially be used as an alternative therapeutic agent against T. rubrum infections.