We describe a 57-year-old woman with a history of nail dystrophy since the age of 11 years. Multiple nail clippings were negative and multiple empirical treatments for presumed onychomycosis were unsuccessful. The patient has a daughter with classical incontinentia pigmenti. Molecular genetic analysis was positive for the NEMO gene deletion on the X chromosome, confirming the diagnosis of incontinentia pigmenti. Nail dystrophy was the sole feature of the disease in our patient.