Objectives. We examined the level of persistence (remaining on therapy) and compliance (taking the medication according to directions) and its impact on the effectiveness of therapy in patients with postmenopausal osteoporosis (PMO) treating with combination medication containing 70 mg alendronic acide and 2800 IU colecalciferol - Fosavance under the supervision of medical practitioners. Material and methods. The trial was performed in the form of 2-year prospective observational multicenter study that included 373 patients with PMO aged 40-88 years, initiated therapy with Fosavance under the supervision of 20 physicians had their medical practice in Moscow (18) or Moscow region (2). Patient compliance and persistence with therapy assessed every 6 months for 2 years, the effectiveness of treatment evaluated in 2 years on the dynamics of bone mineral density (BMD) and indicators of quality of life (QOL) by the SF-36 scale. Results. 70.2% of recruited in the study PMO patients prematurely stopped therapy with Fosavance, including 41% - in the first 6 months. Among the patients who dropped out, 42.7% were lost to follow by medical practitioners, 28.6% switched to another drug therapy, 19.1% had no money to buy medication. 22.5% from 111 women who continued treatment after 2 years were non-compliant due to the high cost of therapy (52%), optionality with the purchase of the drug at the pharmacy (28%) or taking pills (16%), or lack of medication in the pharmacy (4%). There were no statistically significant differences in BMD change in compliant (CP) and non-compliant patients (NCP) in lumbar spine, trochanter and total proximal femur in 2 years. But the increase in femoral neck BMD was higher in CP vs. NCP (=1.97% [-1.41; 13.3] and =-2.03 [-10.4 5.20], p=0.0267). CP had greater increase in QOL by SF-36 scoring at role-physical functioning (=5 points [0; 25] at CP vs. =0 points [-50; 0] at NCP, p=0.0195), role-emotional functioning (=50 points [0; 84] and =0 points [-100; 0] respectively, p=0.0001) and social functioning (=13 points [-13; 25] and =-13 points [-25; 0] respectively, p=0.0048). Conclusions. Low adherence to Fosavance negative impact on the effectiveness of treatment PMO and QOL. At the initiation of therapy it's requires close interaction between the doctor and the patient, maintaining patients on regular treatment motivation and selection of the drug taking into account convenience of the reception.