Abstract: Background: Abnormal expression of several microRNAs (miRNAs) has been demonstrated in many types of cancer tumor tissue. The miR-10b and miR-21 are an oncogenic miRNAs which play role in proliferation and invasion of Breast Cancer (BC) tumorigenesis. The aim of this study was to evaluate the miR-21 and miR-10b expression in BC in West Sumatran women, Indonesia. Materials and Methods: A total of 40 samples, consisting of 30 samples of breast cancer tissues (BC) and 10 samples of fibroadenoma tissues (FATs) as control and non-cancerous were analyzed. The miR-21 and miR-10b expression of each sample were investigated by using realtime PCR, followed by universal Reverse Transcription (RT) then real-time PCR amplification with specific primers. Hsa-miR-16-5p LNA PCR primer was used as an endogenous control. Results: The results showed that the expression level of miR-21 was more than 4 times higher in BC than in FATs. The expression level of miR-10b was lower in BC than FATs, by a factor of 3.34 fold. Both these differences were statistically different (p = 0.001). Conclusion: In this study it was concluded that for this sample of West Sumatran Women miR-21 expression in BC was higher than in FATs, whereas miR-10b was lower in BC than in FATs.