Background: Risk determination of breast cancer metastases is important for clinicians to be able to estimate the adequate therapy for the patients provide the basis for clinical reasoning and explanation of the possibility of metastasis to breast cancer patients who are in treatment. However, current prediction models have low accuracy and molecular determinants tend to have a high evaluation cost. Bioscore had emerged as a new reliable option in determining the risk of metastases in breast cancer, but it is not widely applied yet. Therefore, it is necessary to study its capability in determining risk of metastasis in the clinical setting in order to validate its future application.Objective: To determine the bioscore scoring system as a risk determination for metastases in breast cancer at Sanglah Hospital, Denpasar.Methods: This research was a nested case control study involving 32 subjects in two groups, namely metastatic and non-metastatic breast cancer groups. All patients are registered in the Cancer Registry Data at Sanglah Central General Hospital. The parameters in this study were age, stage, grading, hormonal status, HER2 status, menopausal status, metastatic status and bioscore values. Data were tabulated and statistically analyzed using SPSS 25.Results: From all subjects, the average patient age of 51.50 (±8.491) years, ranging from 31 - 72 years old. The bioscore was significantly associated with all research variables. Risk analysis showed that breast cancer patients with a high bioscore (5-7) has a significantly higher risk of metastasis (OR: 21.00; 95% CI: 5.620 – 78.475) compared to those with low bioscore (1-4).Conclusion: The bioscore scoring system may have a significant value in predicting metastasis in breast cancer patients. However, its application still needs further and more comprehensive studies to validate its application in breast cancer management.