The syndrome of single incisor belongs to the group of midline malformations and is characterized by a single incisor in the patient's maxilla. A growth hormone deficiency (GHD) can be associated. We report about two of our patients with this syndrome. A GHD was diagnosed at the age of 11.0 and 7.6 years, respectively, although a single incisor had already been present during their first dentition. The first patient was treated with HGH to a chronological age of 18.6 years (final height 168 cm), the second patient is still on therapy. The growth of children with craniofacial dysmorphic features must be controlled closely in order to diagnose a GHD in time.