Incontinentia pigmenti (IP) is an X-linked, dominantly inherited, multisystem disorder affecting the skin and other sites, including the teeth, nails, hair, eyes and central nervous system. IP is predominantly seen in females, with few male cases described. It is caused by mutations in the IKBKG gene located on Xq28 (1). We describe a male patient with IP caused by post-zygotic mosaicism for the common deletion of the IKBKG gene. We delineate the diagnostic challenges, and emphasize the importance of early clinical recognition and diagnosis in order to initiate appropriate treatment and offer genetic counselling.