Hypohidrotic ectodermal dysplasia (HED) is an inherited disorder characterized mainly by hypotrichosis, hypohidrosis, a characteristic facial appearance, hypodontia/anadontia and malformed teeth. The aim of this study was to assess the pattern of missing teeth and tooth malformations in children affected with HED in Istanbul, Turkey. Clinical and radiological findings of 16 children (9 boys and 7 girls) diagnosed with HED attended the clinics of Pediatric Dentistry, Istanbul Univ., were reviewed; the pattern of missing and malformed teeth in primary and permanent dentition was evaluated. Percentages of children affected with anadontia, oligodontia and hypodontia were found as 12.50%, 81.25% and 6.25%, respectively. The most frequently missing teeth were noted as primary lateral incisors (27.48%) in the primary dentition and lateral incisors and second premolars in the permanent dentition. A pattern of symmetry was assessed for agenesis of teeth. Peg shaped/tapered and conical morphology was observed in total of 11 primary and 10 permanent teeth. Radiological examination exhibited root abnormalities in 13 teeth. Girls showed higher frequency of root malformations; and no significancy was found in data of prevalences of agenesis and crown tooth malformations regarding gender. Data of missing and malformed teeth in both dentition of children with HED has emphasized the need of early multidisciplinary treatment options for dental and psychological rehabilitation.