Although widely used, the value of prostate-specific antigen (PSA) in the detection of prostate cancer is controversial. The percentage of free PSA increases the specificity of PSA, but results are not enough. Prostate cancer gene 3 (PCA3) has been proposed as an option that may complement these markers in the detection and management of early prostate cancer. Our aim has been to review the value of PCA3 as tumor marker. The available results suggest that PCA3 is particularly useful to select in which patients the biopsy should be repeated when the first biopsy was negative. However, some points should be specified with further studies, including the most appropriate PCA3 cutoff level and the significance of a high PCA3 score in patients with negative biopsy. False-negative results are also a conflictive point in the use of PCA3, because prostate cancer, including aggressive tumors, may be present in patients with a low PCA3 score. Probably, a proper interpretation of this test requires its management together with other tests, through multivariate models for the detection of prostate cancer. On the other hand, several studies showed the relation between PCA3 score and Gleason score, and also the utility of PCA3 to select patients for active surveillance. To summarize, the available studies show the utility of PCA3 in the detection and management of early prostate cancer, although some aspects referred to its use need to be retested after further studies to confirm the actual value and the limitations of this test.