Oral findings in 45 patients with Rubinstein-Taybi syndrome living in The Netherlands are compared with those from the literature. The main non-dental findings were thin upper lip, small oral opening, pouting lower lip, retro/micrognathia, and apparently higher arched, narrow palate. Cleft uvula, cleft palate, or, rarely, cleft upper lip can be part of the syndrome. Timing of the eruption of deciduous and permanent dentition is normal. Sixty-two percent of patients have malpositioned, crowded teeth. Marked caries was found in 36% and was possibly caused by problems in dental care due to the small opening of the mouth, malposition and malformation of the teeth, and non-cooperation of the patients. Hypodontia, hyperdontia, and natal teeth can be manifestations of the syndrome. In 73% of all patients and in 92% of all permanent dentitions, talon cusps were found. Two or more talon cusps are rarely found in the normal population or other syndromes. Therefore, this finding strongly supports the diagnosis of Rubinstein-Taybi syndrome in patients in whom this diagnosis is suspected.