Angelman syndrome is characterized by developmental delay, absence of speech, motor impairment, epilepsy, and a peculiar behavioral phenotype with happy demeanor. It is caused by lack of expression of the UBE3A gene, which can result from various abnormalities of chromosome 15q11-q13. Interictal high-amplitude rhythmic electroencephalographic (EEG) patterns are distinctive and should be differentiated from epileptic activity. Patterns of seizures, including type, age of onset, other clinical features, and EEG features of patients with Angelman syndrome may show some resemblance to defined epileptic syndromes. Correct characterization of their epilepsy is therefore important for both management and prognosis. Surveys of antiepileptic drugs used in patients with Angelman syndrome have suggested that valproic acid is the most commonly used. Non-pharmacological management is rarely considered, despite the relatively high prevalence of drug resistance. Ketogenic diet has been effective in a few cases.