The microRNAs (miRNAs) are short non-coding RNAs that regulate gene expression. The expression of microRNAs is not fully known in brain metastasis mechanism, but there are evidences that they are important in the development of brain and breast tumors. The aim of our study was to measure the expression of the microRNAs: miR-221, miR-133b and miR-126 and the genes: MGMT, XIAP and IDH2.We utilized for this study brain metastasis samples from patients diagnosed with breast cancer. For the analysis of the samples we used the quantitative polymerase chain reaction (qPCR) for gene expression quantification of the genes (MGMT, XIAP and IDH2) and microRNAs (miR-221, miR-133b and miR-126). The miR-133b and miR-221 were significantly down-regulated in the brain metastasis and breast cancer samples. All three genes didn’t have any statistically significant differences. However, MGMT and IDH2 was up-regulated in brain metastasis, and XIAP was up-regulated in breast cancer. The miR-133b and miR-221 was down-regulated in the brain metastasis and breast cancer samples.