Osteoporosis (OP) is a progressive metabolic bone disease caused by disturbed balance between bone formation and bone resorption. Osteoporotic fractures lead to a deterioration in the quality of patients’ life due to high morbidity and mortality, and the economic burden of osteoporotic fractures is expected to increase. Various tools have been developed to assess the risk of osteoporosis in the clinical practice. The Osteoporosis Self-Assessment Tool (OST) is used to predict osteoporosis and is suitable for self-assessment. The purpose of this study is to assess the ability of the OST score to predict the risk of OP. 180 postmenopausal women with a mean age of 61 ± 13 years (38-86 years) were included in the study. The OST score was evaluated using the formula: (body weight  age) × 0.2. Patients were divided into three groups according to the risk of OP: low risk (> -1), moderate risk (-1 to -4) and high risk (<-4). Based on the total lumbar spine T-score, measured by dual-energy X-ray absorptiometry (DEXA), the actual number of the women with OP was established. According to the OST score, 22 women were in the high risk group, 41 women in the moderate risk group, and 117 women in the low risk group. There was a correlation between the risk of OP calculated with OST and the number of patients with OP, established by DEXA measurement - with increased risk of OP, the number of the women with OP also increased (p = 0.000). The percentage of the women with osteoporosis is highest in the high risk group and lowest in the low risk group. In the high risk group, 95.5% of the women had a diagnosis of osteoporosis. These results demonstrate the good ability of OST score to predict the risk of OP in the Bulgarian population.