This is the final version of the article. It first appeared from Springer via http://dx.doi.org/10.1007/s00345-015-1650-0 ; Purpose To compare histological outcomes in patients undergoing MRI-transrectal ultrasound fusion transperineal (MTTP) prostate biopsy and determine the incremental benefit of targeted cores. Methods 76 consecutive patients with 89 MRI-identified targets underwent MTTP biopsy. Separate targeted biopsies and background cores were obtained according to a standardized protocol. Target biopsies were considered of added diagnostic value if these cores showed a higher Gleason grade than non-targeted cores taken from the same sector (Group 1, n = 41). Conversely, where background cores demonstrated an equal or higher Gleason grade, target cores were considered to be non-beneficial (Group 2, n = 48). Results There was no significant difference in age, PSA, prostate volume, time-to-biopsy, or number of cores obtained between the groups. A greater proportion of target cores were positive for cancer (158/228; 69.3%) compared to background (344/1881; 18.38%). The median target volume was 0.54 cm^3 for Group 1 (range 0.09 - 2.79 cm^3), and 1.65 cm^3 for Group 2 (0.3 - 9.07 cm^3); p