The use of botanical extracts for their perceived therapeutic benefits has gained increased popularity in this country and abroad. In particular, tea tree oil (the extracted oil of Melaleuca alternifolia) has gained widespread use for its purported antimicrobial and therapeutic effects. In parallel with this increased use is an expanding series of reported adverse effects, including allergic contact dermatitis, systemic contact dermatitis, linear immunoglobulin A disease, erythema multiforme-like id reactions, and systemic hypersensitivity reactions. We present a review of tea tree oil with regard to its history, chemistry, purported medicinal uses, and possible adverse cutaneous effects.