Overnight polysomnography was performed in 10 subjects with tuberous sclerosis (TS) and partial epilepsy in order to investigate the relationships between sleep organization, sleep disorders and epilepsy. Sleep architecture abnormalities were observed in 9 cases. Compared with ten healthy age-matched controls, the TS group showed a shorter total sleep time, a reduced sleep efficiency, a higher number of awakenings and stage transitions, an increased wake after sleep onset and stage 1 and a decreased REM sleep. Children with seizures showed a more disrupted sleep architecture compared with seizure-free children. Sleep disorders in TS were mainly due to sleep-related epileptic events and were more evident in children who showed large bifrontal or temporal tubers on MRI.