The aim of study was to analyze and investigate the severity of adverse reactions (AR) on drugs used for arterial hypertension treatment in patients living in the Republic of Crimea for the period 2011—2016.Materials and methods. We studied notification cards about AR registered in the regional database of spontaneous messages ARCADe. We analyzed 211 notification cards about AR in patients with proven arterial hypertension diagnosis (ICD code П0—П5).Results. Drugs from the groups of angiotensin-converting enzyme inhibitors and slow calcium channel blockers most often cause AR, among them enalapril and amlodipine are the absolute leaders. AR occurred less frequently in application of drugs from the groups of в-blockers and angiotensin IIreceptor blockers. The study of the clinical manifestations of AR showed that most of them were allergic reactions of varying severity (skin itch, urticaria, swelling of lips, eyelids, tongue). The number of such cases was 70 (33.2 %) from all registered cases of AR on antihypertensive drugs. Examination of the outcomes of AR in patients taking antihypertensive drugs showed that the development of temporary disability was observed in 19 (9 %) cases, the hospitalization of outpatients as a result of AR development on drugs was required in 7 (3.3 %) cases, and in 2 cases patients had to prolong hospitalization. Life-threatening conditions in the form of Quincke’s edema were reported in 13patients. In the remaining 170 (80.6 %) cases AR were not serious and did not cause the above consequences. Assessment of AR severity revealed that mild AR were most common, much less often antihypertensive drugs caused severe AR (the incidence ranged from 5 to 13 %, depending on the method for severity assessment).Conclusion. The obtained results confirm our previously published data that in the structure of AR on antihypertensive drugs, bulk of the reports associated with angiotensin-converting enzyme inhibitors. Most often antihypertensive drugs caused mild AR.