A 4-year-old boy with Sotos syndrome had repeated urinary tract infections. Complete right ureteral duplication and bilateral vesicoureteral reflux were, diagnosed, and antireflux surgery was performed. This child also had elevated serum creatine kinase levels and atypical absence seizures. The associations of ureteral duplication, continuously elevated serum creatine kinase level, and atypical absence seizure have not been reported previously in Sotos syndrome.