Objective: To investigate the changes in the retinal microcirculation in multiple sclerosis (MS) patients by swept-source optical coherence tomography angiography (SS-OCTA). Patients and Methods: Thirty-seven patients with relapsing-remitting MS and 40 healthy volunteers were included into this cross-sectional study. Clinical history, Expanded Disability Status Scale and duration of MS were collected. SS-OCTA by deep range imaging (DRI) OCT measurements were performed on all subjects. Macular perfusion parameters including superficial and deep foveal avascular zones (FAZs, FAZd, respectively) (%), vascular densities of superficial capillary plexus (SCP) (%), deep capillary plexus (DCP) (%) and choriocapillaris (CC) (%) were compared with healthy subjects. Results: Vascular densities of SCP, DCP and CC were found to be statistically lower in the study group compared to the control group (p = 0.02, p = 0.03, p = 0.03, respectively). FAZs and FAZd, areas were significantly higher in the study group (p = 0.02, p = 0.02, respectively). Central macular thickness and subfoveal choroidal thickness were significantly lower than in the control group (p = 0.015, p = 0.047, respectively). Conclusion: Evaluation of retinal blood flow in patients with MS is useful both for understanding the physiopathology of the disease and in the clinical follow-up.