The aim of this study was to evaluate the diagnostic and predictive value of sarcosine, included in a panel of urinary oncometabolites (alanine, β-alanine, ethanolamine, GABA, kynurenine, leucine, and isoleucine) and their correlation with PSA and Gleason score in patients, diagnosed with prostate cancer. Here, KLK3 is linked to prostate cancer.