This report describes 11 patients with Rubinstein-Taybi syndrome (RTS) and patellar dislocation. The age at diagnosis of patellar dislocation ranged from birth to 16 years. Ten patients had chronic dislocations and 8 of 11 had bilateral patellar dislocations. Eight patients required surgical stabilization of the patella; most achieved a good outcome with surgical repair. All families reported that the patellar dislocations impaired developmental skills which improved after surgery. Seven of the 11 patients were described as having other joint abnormalities including congenital dislocations and laxity of the joints. Patients with RTS should undergo regular thorough joint examinations, including the knees, because abnormalities may result in delay of attainment of motor skills.