Introduction Many men with non-clinically significant PCa (N-CSPCa) will not progress to become symptomatic within their lifetime. If we can predict clinically significant PCa (CSPCa), we can prevent patients from unnecessary biopsies, overdiagnoses, and overtreatment. The purpose of this study was to determine whether PSAD and f/t PSA can predict CSPCa (Gleason ≥ 7) in patients diagnosed with prostate cancer on biopsy with a PSA level of 2.5-10 ng/ml or not. Materials and Methods 78 patients who underwent TRUSG-guided prostate biopsy with PSA 2.5-10.0 in our clinic between March 2017 - August 2020 and whose pathology result was reported as prostate adenocarcinoma, were retrospectively evaluated. In addition to the demographic content of the patients, PSA, free PSA, prostate size (with TRUSG), rectal examination findings and prostate biopsy pathology results were recorded. Clinically significant prostate cancer was defined as a Gleason score 7. Results The mean age of the patients was 66.9 ± 8.4, PSA value was 6.9 ± 1.8, free / total PSA ratio was 18 ± 8.1%, and PSA density was 0.150 ± 0.078. The P values of PSA, free PSA, PSAD, f/t PSA, and prostate volume between CSPCa and N- CSPCa groups were 0.010, 0.780, 0.001, 0.084, and 0.030, respectively. The area under the ROC curve (AUC) of the PSAD for predicting CSPCa was 0.719 with a 95% Cl (0.604–0.835), and the standard errors were 0.062 and 0.059, respectively. When PSAD cutoff was 0.130 for predicting CSPCa, sensitivity and specificity were 75% and 63%, respectively. Conclusion PSAD can be used for predicting CSPCa, but f/t PSA can not. PSAD is not a strong stand-alone tool with its sensitivity and specificity, but we suggest that PSAD can be a part of future nomograms for predicting CSPCa and future protocols for active surveillance. Key words:prostate-specific antigen; clinically significant prostate cancer