Toenail disorders account for the majority of foot complaints for which adults seek medical care. Onychomycosis, a fungal nail infection, is the most prevalent. Dermatophytes are responsible for the majority of nail infections and cause varying degrees of nail deformities. While several treatment strategies are available, no one approach (topical, systemic, or mechanical) is highly curative. This article reviews causes, diagnosis, and treatment options for onychomycosis and provides patient education tips to prevent and limit the spread of the disease.