There is a close association between sleep and epilepsy, and this literature review aims to raise issues regarding sleep time control, circadian and ultradian rhythms, epilepsy and its interaction with sleep and circadian rhythm, epilepsy and sleep disorders, and finally epilepsy management and medications. It is mentioned that sleep may provide a hypersynchronous state, as occurs in non-rapid eye movement sleep (NREM), and hyperexcitability, in cyclic alternating pattern (CAP), allowing more frequent interictal epileptiform abnormalities and seizures. In some epilepsy syndromes, seizures occur broadly / or entirely during sleep or on awakening, mainly in childhood, and maybe exacerbated in adults during the sleep or sleep-deprived, and there are the so-called Sleep-related epilepsies that are divided as sleep-associated, sleep-accentuated and arousal/awakening related. Sleep quality may be reduced in patients with epilepsy also due to nocturnal seizures or concomitant sleep disorders. Sleep disorders are common in patients with epilepsy and treatment of them mainly sleep-disordered breathing may improve seizure control. Besides, some parasomnias may mimic seizures, and also they can adversely affect the quality and quantity of sleep whereas antiepileptic therapy can have a negative or positive effect on sleep. Nocturnal epileptic seizures may be challenging to discern from parasomnias, in particular NREM parasomnias such as night terrors, sleepwalking and confusional arousals.