The purpose of the present investigation is to describe and discuss the craniofacial abnormalities in young and adult patients with cleidocranial dysplasia (CCD). Skull radiographs of 52 CCD patients were examined. Thirty-six patients were adult, 16 were between 7 and 16 years old. Facial photographs were available in 30 cases, and in one adult case with cranial CT scans, 3-D reconstructions were carried out. High quality photographs of six CCD skulls were also described. The paranasal sinuses were absent or diminished in all children and most adult patients. An inverted pear-shape of the calvaria and an open anterior fontanelle were present in more than 60% of the cases. In the cranial base an upward distortion of the clivus, an anteverted foramen magnum, and extremely narrow choanae were frequent traits, together with small sella and bulbous dorsum sellae. Nearly all patients and dry skulls showed hypoplasia or absence of nasal bones. The zygomatic arches were diminished or incomplete in all cases. Mandibular morphology was judged to be syndrome specific with the slender, upward-backward-pointing coronoid process. We have concluded that a great part of the abnormal qualitative traits are present to a lesser degree in CCD children, indicating a progressive abnormal development with advancing age. From the present and previous studies on CCD we have hypothesized that on top of their generalized reduction of growth potential, these patients suffer from a combination of skeletal immaturity resulting in deformations and a defective bone remodeling. We have acknowledged the importance of longitudinal investigations in order to ameliorate the understanding of the pathogenesis of CCD and thereby to improve total patient care. Correction of the craniofacial abnormalities may be advocated in the most severe cases of hypertelorism and midfrontal groove, if psychosocial problems occur. Also, patients with major midface underdevelopment might benefit from combined orthodontic/surgical correction.