A composition obtained primarily from plant materials provides antimicrobial activity for use as an anti-fungal agent. The anti-fungal agent is effective in inhibiting the growth of Trichophyton rubrum, the fungus that is the most common cause of Tinea pedis. The composition includes selective mixtures of the origanum oil, menthol, and Atlantic cedarwood oil, thuja oil, cedarwood oil, cinnamon oil, clove oil, cumin oil, fennel oil, peppermint oil, or rosemary oil.