Background: Epilepsy associated with Prader-Willi syndrome (PWS) represents an early and important complication, often not clearly reported and described in the literature. Consequently, there are controversial data about the clinical characteristics of epilepsy and electroencephalographic (EEG) abnormalities found in these patients. Data sources: Based on recent original publications, we have reviewed the different types of seizures and EEG findings in PWS patients, the response to antiepileptic treatment, and the prognosis of epilepsy. Results: The frequency of epilepsy in PWS patients ranges from 4% to 26%. The types of seizure include generalized tonic-clonic seizures, complex partial seizures, atypical absence, staring spells, and myoclonic, tonic and hemiclonic seizures, but the most frequent type is focal epilepsy. Status epilepticus has never been reported. EEG abnormalities are not typical but variable in different patients. However, generalized and focal discharges are the most frequently reported findings. There is no evidence of relationship between the course of epilepsy and frequency, morphology and spread of EEG discharges. However, epilepsy in PWS patients is usually responsive to antiepileptic monotherapy with rapid seizure control and a good outcome. Conclusions: The frequency of epilepsy is higher in PWS patients than in general populations and this complication can be a challenge for the clinicians of these patients. Prospective studies are needed to confirm the good long-term prognosis.