Introduction: We aimed to determine the diagnostic accuracy of the prostate cancer antigen 3 (PCA3) test before performing the first biopsy compared with prostate biopsy for the diagnosis of prostate cancer. Methods: A systematic search was performed in MEDLINE, EMBASE, CENTRAL, LILACS, reference lists, specialized journals in urology and cancer, and unpublished literature. The population was adults with suspected prostate cancer, and the intervention was the measurement of PCA3 in urine samples for the diagnosis of prostate cancer. The quality of studies was evaluated with the Quality Assessment of Diagnostic Accuracy Studies-2 (QUADAS-2) tool. The operative characteristics were determined, and a meta-analysis was performed. Results: Nine studies of diagnostic tests were included based on a cutoff value of 35. The following overall values were obtained: the sensitivity was 0.69 (95% confidence interval [CI] 0.61–0.75); specificity was 0.65 (95% CI 0.553–0.733); the diagnostic odds ratio (DOR) was 4.244 (95% CI 3.487–5.166); and the area under the curve was 0.734 (95% CI 0.674–0.805) with a heterogeneity of 0%. Conclusions: Urinary PCA3 has an acceptable diagnostic accuracy, aids in the study of patients with suspected prostate cancer, and can be used as a guide for directing the performance of the first prostate biopsy and decreasing unnecessary biopsies.