Clinicians need to know about how onychomycosis presents clinically, how to make a definitive diagnosis (which involves identifying the causative organism in each patient prior to initiating therapy), which treatments currently are available and how best to use them, and which new agents are now in clinical trials and may soon be options for therapy. The purpose of the articles in this supplement is to offer a convenient compendium of current information in all of these areas for both clinician and patient. If you would like to receive CME or CNE credits, please click here.