Background: Sleep disorders and factors contributing to poor sleep in multiple sclerosis (MS) patients remain unclear and most of previous studies used subjective scales for sleep assessment. Objectives: We aimed to assess the subjective and objective parameters of sleep by evaluating 8-hour polysomnography in MS patients. Methods: We included 50 MS patients with either relapsing remittent MS (RRMS) or secondary progressive MS (SPMS) and 25 age-and sex-matched controls not diagnosed with sleep disorders. Demographic and clinical characteristics were collected. All participants completed standardized self-report questionnaires including Pittsburg Sleep Quality Index (PSQI), Epworth Sleepiness Scale (ESS), Fatigue Severity Scale (FSS), Beck Depression Index (BDI), Beck Anxiety Index (BAI) scales and underwent history taking, general, neurological examination and nocturnal polysomnography evaluation. Results: We found 82% of MS patients were poor sleepers and 50% of them met the criteria of excessive daytime sleepiness. BDI and BAI scores were significantly higher in poor than good sleepers patients. Thirty six patients (72%) had middle insomnia, 46% had initial insomnia. Nine patients (18%) had higher apnea/hypopnea index versus none of controls. Seventeen patients (34%) had restless legs syndrome and ten (20%) had higher periodic limb movement index versus none of controls. Depression, anxiety, pain, nocturia, fatigue, immunotherapy, high disability and poor quality of life were independent predictors for poor sleep. Conclusions: Overall, 82% of MS patients had evidence of one or more sleep disturbances. Our study confirms that MS causes sleep fragmentation in terms of both macro and microstructure.