An adult cohort with tuberous sclerosis complex was investigated for the prevalence of sleep disturbances and the relationship with seizure variables, medication, and psychological functioning. Information on 35 adults was gathered using four questionnaires: Epworth Sleepiness Scale (ESS), Sleep and Epilepsy Questionnaire (SEQ), Sleep Diagnosis List (SDL), and Adult Self-Report Scale (ASR). In addition, clinical, genetic and electrophysiological data were collected. Of 35 respondents, 25 had a history of epilepsy. A subjective sleep disorder was found in 31% of the cohort. Insomnia scores showed a significant positive correlation with obstructive sleep apnea syndrome and restless legs syndrome scores. Significant correlations were found between daytime sleepiness and scores on depression, antisocial behavior, and use of mental health medication. A subgroup using antiepileptic medication showed high correlations between daytime sleepiness, attention deficits, and anxiety scores. © 2010 Elsevier Inc.