The Gleason grading system remains one of the most powerful prognostic factors in prostate cancer and is the dominant method around the world in daily practice. It is based solely on the glandular architecture performed at low magnification. The Gleason grading system should be performed in needle core biopsies and radical prostatectomy specimens where it shows a reasonable degree of correlation between both specimens, and most importantly, it remains vital in the treatment decision-making process. This review summarizes the current status of Gleason grading in prostate cancer, incorporating recent proposals for the best contemporary practice of prostate cancer grading.