This study reports the physical and radiographic characteristics of 45 patients with Rubinstein-Taybi syndrome living in The Netherlands. All had broad halluces, but only 39 patients had broad thumbs. Microcephaly was present in 35% of patients. In addition to the well-known characteristics, persistent fetal pads, a shawl scrotum, and a high frequency of fractures were found in several patients. Morbidity was mainly determined by the mental handicap, constipation, and recurrent upper respiratory infections, probably due to abnormal anatomy in the craniofacial region. Easy collapsible laryngeal walls may cause problems in sleep and anaesthesia.