Sleep disturbances and epilepsy are common in Angelman syndrome (AS). This study examines seizure variables and sleep in a large AS cohort. Sleep disturbances and epilepsy were assessed in 290 individuals with AS using two questionnaires, including the Behavioral Evaluation of Disorders of Sleep (BEDS). Sensitivity to the sleeping environment, decreased nightly hours of sleep, and a difficulty initiating sleep were significantly correlated with the presence of epilepsy, particularly focal seizures. Use of multiple anticonvulsant drugs was shown to affect sleep. No significant associations were present between molecular subtypes of AS and individual sleep factors. Sleep problems appeared to be associated with epilepsy in individuals with AS, especially with focal and absence seizures and multiple seizure types. Results were consistent with those of prior studies assessing sleep in AS. Severity of epilepsy and use of anticonvulsant drugs may be related to a higher degree of sleep disturbance in this population.