Previous researchers have demonstrated that microRNAâ505 (miRâ505) is negatively correlated with progression in various malignancies. However, the detailed function and molecular mechanisms of miRâ505 have yet to be completely elucidated in prostate cancer (PCa). The present study initially identified the potential role of miRâ505 in PCa using in vitro experiments, and demonstrated that restoration of miRâ505 inhibited proliferation, invasion and migration, yet induced cell cycle arrest and promoted apoptosis in PCa cells. The present study also demonstrated that the expression of neuronâglialârelated cell adhesion molecule (NRCAM) was markedly upregulated in PCa cells when compared with benign prostate epithelium. A luciferase reporter assay demonstrated that miRâ505 directly targeted NRCAM in PCa cells. In addition, NRCAM stimulation antagonized the inhibitory effects of miRâ505 on the proliferation, migration, and invasion of PCa cells. Furthermore, lower levels of miRâ505 and higher levels of NRCAM may serve as a predictor of worse biochemical recurrenceâfree survival or diseaseâfree survival in patients with PCa. In conclusion, the present study revealed the inhibitory effects of miRâ505 on PCa tumorigenesis, which potentially occur by targeting NRCAM. The combined analysis of NRCAM and miRâ505 may predict disease progression in patients with PCa following radical prostatectomy.