miRNAs are short noncoding RNAs able to regulate specific mRNA stability, thus influencing target gene expression. Disrupted levels of several miRNAs have been associated with prostate cancer (PC), the leading cause of cancer death among men and the fifth leading cause of death worldwide. Herein, we investigated whether miR-145, miR-148, and miR-185 circulating levels in plasma could be used as molecular biomarkers, to allow distinguishing between individuals with benign prostatic hyperplasia, precancerous lesions, and PC. One-hundred and seventy urological clinic patients with suspected PC who underwent prostate biopsy were recruited. Total RNA was isolated from plasma, and TaqMan MicroRNA assays were used to analyze miR-145, miR-185, and miR-148 expression. First, differential miRNA expression among patient groups was evaluated. Then, miRNA levels were combined with clinical assessment outcomes, including results from invasive tests, using multivariate analysis to examine their ability in discriminating among the three patient groups. Our results suggest that miRNA is a promising molecular tool for clinical management of at-risk patients.