Onychomycosis is not just a cosmetic problem. It is a common disorder that may be a reservoir of infection and lead to significant medical problems. In addition, onychomycosis may cause a substantial decrease in quality of life. An understanding of the disorder and updated management is important for all health care professionals. Onychomycosis is the most common nail disorder in adults. It is four to seven times more frequent in toenails, where it often involves several nails. It is a progressive disease, and although not life threatening it is inappropriately considered purely a cosmetic problem, with some physicians still believing there is no need to treat. The fungal infection usually begins in the nail bed, and often extends to the nail plate. Onychomycosis is unsightly and can be uncomfortable; with discoloration of the nail plate and more severe disease resulting in loss of the nail plate altogether. Onychomycosis may become a source of more widespread fungal lesions, spreading to other nails, body sites (groin, skin, scalp), and even to family members.