To determine if Gleason score exhibits any significant variation between African-Americans and Caucasian men with prostate cancer.We conducted a retrospective cohort study. Inclusion required diagnosis of prostate cancer and reporting it to the TriHealth tumor registry from 1995–2005. We excluded individuals of any other ethnicity than the two of interest (N=15) and individuals without a reported Gleason score (N=82). For each patient we collected data on ethnicity, Gleason score, age, American Joint Committee on Cancer (AJCC) stage, insurance status, and surgery. Gleason score was divided into low-grade (1–6) and high-grade disease (7–10). Institutional Review Board approval was obtained prior to data collection.A total of 1916 patients, (1476 Caucasians, 440 African-Americans) were eligible for inclusion in the study. There was no significance difference between either ethnicity for age, insurance status, and the percentage of men needing a transurethral resection of the prostate (TURP). There was no difference between either ethnicity for stages 0, 1, and 4. African-Americans were more likely to have stage 2 disease, while Caucasian men possessed more stage 3 disease (p<0.05). African-Americans were significantly more likely to not have any prostate surgery (p<0.05). Caucasian men were more likely to have a prostatectomy. African-American men with prostate cancer were significantly more likely to have a high-grade Gleason score compared to Caucasian men (OR=1.22, 95% CI=1.11–1.35).African-American race is a predictor of more advanced Gleason score at the time diagnosis of prostate cancer.