The aim of the study was to determine the antifungal effects of the essential oil of Thymus broussonetii Boiss (EOT), an endemic plant in Morocco against Candida albicans, Aspergillus fumigatus and the dermatophytes. EOT was extracted by steam distillation. A suspension of up to 500 µL of C. albicans at a concentration of 10⁸ CFU mL⁻¹ and A. fumigatus at a concentration of 10¹⁰ spores mL⁻¹ were inhibited by 20 µL of EOT incorporated in tubes containing 4 mL of Sabouraud broth. In Sabouraud-chloramphenicol agar slants containing different concentrations of essential oil, 5 × 10⁴ A. fumigatus spores were inhibited by 6 µL (0.0015 mL mL⁻¹) of the EOT. It has shown good anti-C. albicans and anti-A. fumigatus activity. All the dermatophytes tested were inhibited by 3 µL (0.00075 mL mL⁻¹) of EOT; the latter has the potential to be a good alternative to the conventional antifungal drugs which are usually expensive and with high toxicity.