Epilepsy is one of the most common presentations associated with chromosome aberrations. Detailed descriptions of some aberration-specific epileptic and electroencephalographic (EEG) phenotypes have been reported (i.e., Angelman syndrome, ring 20 etc.). However there is limited and mixed information about the characteristics of epilepsy related to trisomy 18. Thus a common seizure phenotype has not been characterized yet. Here we describe in detail a patient with refractory epilepsy and partial 18q trisomy.