Harlequin ichthyosis represents the most severe form of nonbullous ichthyosis. It is inherited in an autosomal recessive pattern and very rare. This disease destroys the skin's barrier system and severe cutaneous infections develop in affected newborns. Malformations of ears and nose, and hypoplasia of fingers and nails are seen. It is usually lethal in the neonatal period. A case of Harlequin ichthyosis is herein reported and discussed. © Gülhane Askeri Tip Akademisi 2007.