Background: Sleep disorders are common in multiple sclerosis (MS) patients. These disturbances detrimentally impact both their physical and mental well-being, leading to increased difficulties in executing everyday tasks. To date, there is a lack of comprehensive research regarding the influence of transcranial direct current stimulation (TDCS) on sleep in MS patients. Purpose: This randomized controlled trial was conducted to assess the TDCS effect on sleep subjectively and objectively in MS patients.