The aim of this study is to identify micro-ribonucleic acid (microRNA) and its target, in addition to their relationship to the outcome in breast cancer (BC). To achieve this aim, we investigated microRNA-10b (miR-10b) and minichromosome maintenance complex component 5 (MCM5 mRNA) expression in 230 breast tissue samples by real-time PCR and semiquantitative conventional RT-PCR, respectively. Relapse-free survival (RFS) associated with miRNA-10b and MCM5 mRNA were tested by Kaplan-Meier survival analysis. The impact of miRNA-10b andMCM5 mRNA expression on the survival was evaluated by Cox proportional hazard regression model. The expression of miRNA-10b and MCM5 mRNA was positive in 86.4 and 79.7 % breast cancer patients, respectively. The overall concordance rate between miRNA-10b and MCM5 RNA was 90.4 %. The median follow-up period was 50 months. The survival analysis showed that high levels of both miR-10b and MCM5 were associated with short relapse free survival of BC. We identified MCM5 mRNA expression changes consistent with the miRNA-10b target regulation. Thus, we could consider miRNA-10b and MCM5 mRNA as prognostic markers and potential therapeutic targets in breast cancer to be applied to other patient data sets.