This study aimed to investigate the effect of microRNA-605-3p (miR-605-3p) on cell proliferation, invasion and migration in prostate cancer cells, as well as its effects on the Enhancer Zeste Homolog 2 (EZH2) expression and the potential regulatory mechanisms.,Quantitative Real Time-Polymerase Chain Reaction (qRT-PCR) was applied to detect the miR-605-3p expression in 52 pairs of Prostate Cancer (PCa) tissues and normal tissues, and to analyze the relationship between miR-605-3p expression and PCa pathological parameters. MiR-605-3p mimics were transfected into PCa cell line PC-3 and DU145 to achieve miR-605-3p overexpression. Then, Cell Counting Kit-8 (CCK-8), cell colony formation assay and transwell invasion and migration assay were performed to analyze miR-605-3p's effect on the biological function of prostate cancer cells. Finally, the potential mechanisms of downstream genes were explored through bioinformatics analysis and recovery experiments.,We found that miR-605-3p expression in PCa was markedly lower than that in normal tissues. Patients with low miR-605-3p expression had higher tumor stage, higher incidence of lymph node metastasis and distant metastasis. In vitro analysis showed that miR-605-3p overexpression leads to a significant decrease in cell proliferation, invasion and migration ability. Subsequently, it was verified in cell line and tissue that EZH2 expression was remarkably increased in PCa, which was negatively correlated with miR-605-3p expression. In addition, the recovery experiment found that EZH2 can counteract the role of miR-605-3p in PCa, together they affected the malignant progression of PCa.,MiR-605-3p was significantly associated with PCa stage, lymph node metastasis and distant metastasis and the poor prognosis; besides, it can inhibit the malignant progression of PCa. In addition, the study showed that miR-605-3p may inhibit the proliferation, invasion and migration ability of PCa by regulating EZH2.