Incontinentia pigmenti is a rare, dominantly X-linked genodermatosis characterized by multisystemic involvement that is lethal prenatally in the majority of affected males and shows great clinical variability when it is expressed in women. Recently it has been shown that mutations of the gene NEMO/IKK-g located in Xq28 cause the expression of the disease, being only one mutation responsible for approximately 80 % of the cases. The diagnosis of incontinentia pigmenti is performed based on clinical features and family history with the support of histological findings. Nevertheless, as the gene responsible for the phenotype of the disease has been identified, a genetic study may be employed for doubtful cases. We report three cases of this entity (two women and one man) in different clinical stages of development that show the broad clinical spectrum we may encounter in the clinic.