Aims: Circulating microRNAs (miRs) have been investigated as promising novel biomarkers for cancer diagnosis and prognosis. The aim of this study was to evaluate the expression level of plasma miR-106a in patients with epithelial ovarian cancer (EOC) and investigate its clinical significance. Materials and Methods: By using qRT-PCR, the authors compared plasma miR-106a expression in 95 EOC patients and 100 healthy volunteers. The association between plasma miR-106a level and clinicopathological factors was also analyzed. Furthermore, they explored whether plasma miR-106a could serve as a useful biomarker for EOC diagnosis and prognosis. Results: Plasma miR-106a was up-regulated in EOC patients compared with healthy controls (p < 0.01). High plasma miR-106a levels were significantly associated with advanced FIGO stage, high CA125 expression, poor cancer differentiation, and shorter overall survival. ROC curve analysis showed that plasma miR-106a was capable of distinguishing EOC from control subjects. Multivariate Cox regression analysis confirmed high plasma miR-106a expression as an independent unfavorable prognostic factor for EOC. Conclusions: Plasma miR-106a was upregulated in EOC patients and might serve as a novel non-invasive diagnostic and prognostic biomarker.