Ectodermal dysplasia is a hereditary disorder characterized by the abnormal development of certain ectodermal-origin tissues and structures. Hypohidrotic type is the most commonly observed form of ectodermal dysplasia. Diagnosis is based on the absence or decrease of sweat glands. Dental treatment of oral deficiencies characteristic of this syndrome is commonly quite complex. Physiological and psychosocial reasons dictate the importance for these patients to receive dental treatment at early ages. The present clinical report describes characteristics and prosthodontics treatment of two siblings afflicted with hypohidrotic ectodermal dysplasia.