Four cases of regional odontodysplasia are described. Clinically erupted teeth appear hypoplastic and are often mobile. The radiographic appearance has given rise to the term 'ghost teeth' and the cases presented demonstrate this with short roots which are less well calcified than normal teeth. Clinical and radiographic findings showed that this condition affects only one side of the jaw, but can be seen in any part of the upper or lower jaws. This article represents cases in different parts of the mouth with varying degrees of involvement.