Congenital pseudarthrosis of the clavicle is an unusual and poorly documented entity. When the literature in English was reviewed, 18 documented cases were found. In a 19th case which we report, etiology and pathogenesis remain unresolved. Mechanical factors are strongly suggested by the virtually exclusive occurrence of the lesion on the right side. The differential diagnosis appears to lie between cleidocranial dysostosis and a birth fracture. Treatment by operative means has been uniformly successful if secure internal fixation is used and may be indicated for cosmesis. Little or no functional impairment is to be expected in untreated patients.