Objectives: The aim of the study was to determine occurrence, intensity and type of primary headaches in patients with relapsing-remitting multiple sclerosis, to determine the impact of primary headaches on the quality of life of RRMS patients and the impact of MS therapy on the development of primary headaches. Study Design: A cross-sectional study. Patients and Methods: Thirty patients with RRMS participated in the study, 27 of them had primary headache comorbidity. A self-created questionnaire for this research was used as a research instrument. The SF36-v2 generic questionnaire was used to assess health-related quality of life. The intensity of the headache was determined using a visual analog scale (VAS). Respondents participated in the study during their stay in the Day Hospital at the Clinic of Neurology, Clinical Hospital Center Osijek. Results: Based on the results obtained in the voluntarily completed surveys, most subjects with RRMS who have a primary headache suffer from tension headaches. The age of subjects with primary headaches was statistically significantly higher (p = 0.04) than the age of subjects without primary headaches. In terms of statistics, patients with primary headaches clinically develop multiple sclerosis significantly later (p = 0.04) and are diagnosed later (p = 0.01) than those without primary headaches. No statistically significant result of the effect of MS-modifying therapy on the onset and intensity of pain in primary headaches was observed. Statistically significant differences were observed on the SF36-v2 questionnaire in the overall quality of life in patients with and without primary headaches (p = 0.04). Subjects with primary headaches had a significantly worse result in the particles Restrictions of activity due to physical impairment (p = 0.03), in the domain of Physical health (p = 0.01). Conclusion: Primary headaches are a common comorbidity in MS and significantly affect the overall quality of life of multiple sclerosis patients.