Introduction: Medication overuse headache (MOH) is a secondary headache that occurs 15 or more days per month in patients with pre-existing headaches. It results from the excessive (10 or 15 days/month) use of drugs used as acute or symptomatic headache therapy. The Aim: To examine the relationship between demographic parameters, illnesses and habits of life, clinical type and length of previous headache and MOH; clinical features of MOH. Material and methods: The study was conducted at the Clinic of Neurology, Clinical Center of Niš, and included 83 patients (11 men and 72 women) who were first diagnosed with MOH. The mean age of the study cohort was 40.5 ± 11.6 years. The study was performed in strict accordance with the Declaration of Helsinki after informed consent by each participant in the study Approved by the local Ethical Committee. Results: In the study cohort, there were more women (86.7%), non-smokers (59%), those who did not consume alcohol (95.2%), physically inactive (90.4%), those who consumed caffeinated beverages (89.2%), with diseases of the cardiovascular (12%) and osseous joint system (10.8%). MOH was most commonly generated by the transformation of chronic migraine (64%). The duration of MOH until diagnosis was 5.1 ± 5.5 years. The following MOH characteristics were observed: moderate pain (45.8%), bilateral localization (56.6%), temporal presentation (65.1%), and neck tightness (81.9%). Common (41%) and combination analgesics (48.2%) were used most frequently, 15 to 25 days per month. The impact of MOH on daily life was assessed as significant (HIT - 65.4 ± 5.5), correlating with the duration of earlier chronic headaches (r = 0.327, p = 0.003). Conclusion: MOH is generated by the transformation of a previous chronic headache due to overuse of analgesic therapy. MOH significantly affects all aspects of the patient’s life. MOH can be prevented by educating patients, by limiting the use of analgesic therapy, especially in the at-risk group (middleaged women with chronic migraines)