The International Society of Urological Pathology (ISUP) has issued guidelines for the grading of prostate cancer based on a consensus conference held in 2014. The recommendations resulting from the 2014 consensus conference were a further development of 2005 ISUP modified Gleason grading. In the 2014 system, morphological criteria are clarified, including updated definitions of Gleason pattern 4. In addition to the continued reporting of Gleason scores, we also recommend that Gleason scores ≤6, 3 + 4 = 7, 4 + 3 = 7, 8 and 9–10, respectively, be reported as five groups, i.e. ISUP grades 1–5. This new grading system has the dual benefit of predicting patient outcome as well as facilitating patient communication.