Background: Prostate cancer (PCa) is the second leading cause of cancer death in men. Several articles have reported that microRNA-21 (miR-21) and microRNA-30c (miR-30c) have diagnostic values for PCa, but the results are inconclusive. In order to precisely assess the diagnostic values of miR-21 and miR-30c for PCa, this meta-analysis is performed. Methods: Articles were searched in the databases of PubMed, Embase, and Web of Knowledge (search date: September 6, 2018). Studies were included if they were designed to evaluate the diagnostic performance of miR-21 or miR-30c for PCa. Using Stata 12.0 and Meta-Disc 1.4, the pooled sensitivity (SEN), specificity (SPE), positive likelihood ratio (PLR), negative likelihood ratio (NLR), diagnostic odds ratio (DOR), and area under curve (AUC) of the summary receiver-operating characteristic (SROC) curve with the corresponding 95% CI were calculated. Results: Overall, ten studies (six studies for miR-21 and four for miR-30c) involving1,371 participants were included in this meta-analysis. For miR-21, the pooled SEN and SPE were, respectively, 0.91 (95% CI: 0.87-0.94) and 0.88 (95% CI: 0.82-0.93), the pooled PLR and NLR were, respectively, 7.74 (95% CI: 4.81-12.47), 0.1 (95% CI: 0.06-0.15), the DOR was 77.64 (95% CI: 34.64-174.02), AUC of SROC was 0.95 (95% CI: 0.93-0.97). For miR-30c, the pooled SEN and SPE were, respectively, 0.74 (95% CI: 0.65-0.81) and 0.78 (95% CI: 0.72-0.83), the pooled PLR and NLR were, respectively, 3.39 (95% CI: 2.69-4.26), and 0.34 (95% CI: 0.26-0.44), the DOR was 10.06 (95% CI: 6.96-14.55), and AUC of SROC was 0.83 (95% CI: 0.79-0.86). Conclusion: For PCa, miR-21 is a good diagnostic biomarker and miR-30c is a moderate diagnostic biomarker.