The relationship between sleep and brain lesions remains unknown in patients with multiple sclerosis (MS) and is currently under investigation. Sleep deprivation and reduction in the quality of sleep occur as a result of the direct involvement of the specific central nervous system structure. Therefore, we investigated the relationship between demyelination locations and sleep parameters such as sleep efficiency and respiratory disorders. The polysomnography measurements and brain magnetic resonance imaging (MRI) of 28 patients with relapsing-remitting MS were examined. The MRI results were evaluated using standardized maps to depict voxel-wise probability distribution of demyelination lesion load for patients. First, supratentorial and infratentorial lesion loads were evaluated. Subsequently, the procedure was completed by measuring the lobes and brainstem lesions loads in the brain. There was a negative correlation between the percentage of REM (%) and infratentorial and brainstem lesion loads (rho- 0.396, - 0.418; p < 0.05). Sleep efficiency was adversely affected due to supratentorial lesion loads but it was not statistically significant (p = 0.054). There was no statistically significant correlation between total brain lesion loads and sleep breathing parameters (p > 0.05). Although sleep-related breathing disorders are commonly seen in MS, this study shows that the polysomnography parameter most affected by brain lesion load distribution is REM sleep.