Complex molecular changes that occur during prostate cancer (PCa) progression have been described recently. Whole genome sequencing of primary PCa samples has identified recurrent gene deletions and rearrangements in PCa. Specifically, these molecular events disrupt the gene loci of phosphatase and tensin homolog (PTEN) and membrane-associated guanylate kinase inverted-2 (MAGI2). In the present study, we analyzed the expression profile of MAGI2 gene in a cohort of clinical PCa (n = 45) and benign prostatic hyperplasia (BPH) samples (n = 36) as well as three PCa cell lines. We also studied the expression of PCa-related genes, including PTEN, NKX3.1, SPINK1, DD3, AMACR, ERG, and TMPRSS2-ERG fusion in the same samples. The expression of MAGI2 mRNA was significantly down-regulated in PC3, LNCaP and DU-145 PCa cell lines (p = 0.000), and also in clinical tumor samples (Relative expression = 0.307, p = 0.002, [95 % CI 0.002-12.08]). The expression of PTEN, NKX3.1, SPINK1, DD3, and AMACR genes was significantly deregulated in prostate tumor samples (p range 0.000-0.044). A significant correlation was observed between MAGI2 and NKX3.1 expression in tumor samples (p = 0.006). Furthermore, the inclusion of MAGI2 in the gene panel improved the accuracy for discrimination between PCa and BPH samples with the sensitivity and specificity of 0.88 [CI 0.76-0.95] and 0.83 [CI 0.68-0.92], respectively. The data presented here suggest that MAGI2 gene can be considered as a novel component of gene signatures for the detection of PCa.