MiR-93 is thought to be an onco-miRNA for its capabilities of enhancing tumor growth. The objective of this study was to evaluate the potential predictive value of miR-93 expression in formalin-fixed paraffin-embedded (FFPE) tissues of breast cancer patients. The expression of miR-93 was examined in 101 breast cancer patients and 40 controls using real-time quantitative PCR. We found that miR-93 was markedly upregulated in breast cancer patients compared with controls (p<0.01). The expression level of miR-93 was significantly correlated with miR-24/378 in breast cancer patients. MiR-93 exhibited great capability of discriminating between cancer patients and cancer-free controls by receiver-operator characteristic (ROC) curve analysis. MiR-93 showed 0.866 AUC (the area under the ROC curve) values. The MiR-93 level was found significantly correlated with breast cancer by univariable logistic regression. These results suggest that overexpression of miR-93 in FFPE tissues may serve as an indispensable source for biomarker discovery and validation in breast cancer patients.