Apert`s syndrome is a rare autosomal dominant disease that`s characterized by craniosynostosis and severe syndactyly of both the hands and feet. It is caused by a mutation of the fibroblast growth factor receptor (FGFR) type-2 gene. The development of widespread acne, involving the face, chest, back and forearms, is a characteristic finding at puberty in Apert`s syndrome patients. The acne of Apert`s syndrome patients is generally resistant to conventional therapy, including topical agents and/or oral antibiotics, but it shows a good response to isotretinoin. We report here on a case of acne that was successfully treated with isotretinoin in a teenager with Apert`s syndrome. (Korean J Dermatol 2009;47(5):576~579)