To compare the detection rates of prostate cancer between systematic biopsy and targeted biopsy using a stereotactic robot-assisted transperineal prostate platform. We identified consecutive patients with suspicious lesion(s) on multiparametric magnetic resonance imaging (mpMRI), who underwent both systematic and MRI-transrectal ultrasonography (US) fusion targeted biopsy using our proprietary transperineal robot-assisted prostate biopsy platform between January 2015 and January 2019 at our institution, for retrospective analysis. Comparative analysis was performed between systematic and targeted biopsy using McNemar's test, and the cohort was further stratified by prior biopsy status and Prostate Imaging Reporting and Data System (PI-RADS) v2.0 score. International Society of Urological Pathology (ISUP) grade group (GG) ≥2 cancers (previously known as Gleason grade ≥7) were considered to be clinically significant. A total of 500 patients were included in our final analysis, of whom 67 (13%) were patients with low-risk cancer on active surveillance. Of the 433 patients without prior diagnosis of cancer, 288 (67%) were biopsy-naïve. A total of 248 (57%) were diagnosed with prostate cancer, with 199 (46%) having clinically significant prostate cancer (ISUP GG ≥2). There were no statistically significant differences in the overall prostate cancer and clinically significant prostate cancer detection rate between systematic and targeted biopsy (51% vs 49% and 40% vs 38% respectively; P = 0.306 and P = 0.609). Of the 248 prostate cancers detected, 75% (187/248) were detected on both systematic and targeted biopsy, 14% (35/248) were detected on systematic biopsy alone and 11% (26/248) were detected on targeted biopsy alone. Of the 199 clinically significant cancers detected, 69% (138/199) were detected on both systematic and targeted biopsy, 17% (33/199) on systematic biopsy alone and 14% (28/199) on targeted biopsy alone. There were no statistically significant differences in the detection rate between systematic and targeted biopsy for both overall and clinically significant prostate cancer, even when the cohort was stratified by prior biopsy status and PI-RADS score. Targeted biopsy has greater sampling efficiency compared to systematic biopsy for both overall and clinically significant prostate cancer (23.2% vs 9.8%, P < 0.001 and 14.8% vs 5.6%, P < 0.001). Using our robot-assisted transperineal prostate platform, combined MRI-US targeted biopsy with concurrent systematic prostate systematic biopsy probably represents the optimal method for the detection of clinically significant prostate cancer. © 2020 The Authors BJU International © 2020 BJU International Published by John Wiley & Sons Ltd.