The modern hypothesis of the premenstrual syndrome etiology (PMS) assumes that the disease may be the result of a series of psychoendocrine events that trigger ovulation. It is noted that applying COC with the 7-days pause the pathological symptomatology is renewed. Applying so-called prolonged regimen that provide COCs taking within 63, 126 days or longer allows a decreasing of frequency of complaints related to period. The aim of our study was to compare the efficacy of standard and prolonged regimen of COC with Drosperinone in PMS' treatment. Methods: The clinical symptoms of PMS without treatment within 6 months and longer served as selection criteria. The research was conducted in 2 groups of patients, which were informed about the benefits and possible side effects of prolonged and standard regimen of COC. As including criteria in one or another group was woman's acceptance to take COC in prolonged or standard manner. Each group included 16 patients. The Premenstrual Surveillance Calendar was used for the quantitative evaluation of PMS symptoms. To track the effect of treatment, we compared the severity of symptoms in a lutein phase of a cycle prior to treatment and during treatment. The women in the first group received COC with Drosperinone (Midiana®) in a standard 21-day regimen with a 7-day pause; the lengh of the course - 13 cycles. Patients in group 2 accepted the extended 63-day regimen with a 7-day break; course - 4 cycles. Assessment of treatment efficiency was provided in I group after the sixth and the 13-th cycle of treatment; in group 2 - after the second and 4-th cycle of the treatment. Results: The initial symptoms of PMS were: abdominal distension - 71.4%, swelling - 38.1%; mastalgia - 91.3%; headache - 42.1% of patients, restlessness, worriness - 58.6%, depression - 62.1%, irritability - 81.3%, emotional lability - 76.4% of women. During the second visit at 67.3% of the patients there was an improvement of simptoms: in the first group - 61.3%, in the second - 74.6%. During the final visit, the improvement was observed at 86.7% in the first group and 94.6% in group 2. The most significant changes were related to mood improvement, reduced menstrual flow and decreased appetite. Conclusions: Thus, COC with Drosperinone is not only a contraceptive method but also an effective PMS treatment. From PMS treatment it is preferably a prolonged regimen, which allows to obtain the best results in shorter terms.