Purpose Recent meta-analyses suggest the Metabolic Syndrome (MS) increases high-grade prostate cancer (PC), although studies are inconsistent and few black men were included. We investigated MS and PC diagnosis in black and white men undergoing prostate biopsy in an equal access healthcare system. We hypothesized MS would be linked with aggressive PC, regardless of race. Methods Among men undergoing prostate biopsy at the Durham Veterans Affairs Hospital, medical record data abstraction of diagnosis or treatment for hypertension (≥ 130/85 mmHg), dyslipidemia (HDL < 40 mg/dL), hypertriglyceridemia (≥ 150 mg/dL), diabetes, hyperglycemia (fasting glucose ≥ 100 ml/dL), and central obesity (waist circumference ≥ 40 inches) were done. Biopsy grade group (GG) was categorized as low (GG1) or high (GG2-5). Multinomial logistic regression was used to examine MS (3–5 components) vs. no MS (0–2 components) and diagnosis of high grade and low grade vs. no PC, adjusting for potential confounders. Interactions between race and MS were also tested. Results Of 1,051 men (57% black), 532 (51%) had MS. Men with MS were older, more likely to be non-black, and had a larger prostate volume (all p ≤ 0.011). On multivariable analysis, MS was associated with high-grade PC (OR = 1.73, 95% CI 1.21–2.48, p  = 0.003), but not overall PC (OR = 1.17, 95% CI 0.88–1.57, p  = 0.29) or low grade (OR = 0.87, 95% CI 0.62–1.21, p  = 0.39). Results were similar in black and non-black men (all p-interactions > 0.25). Conclusion Our data suggest that metabolic dysregulation advances an aggressive PC diagnosis in both black and non-black men. If confirmed, prevention of MS could reduce the risk of developing aggressive PC, including black men at higher risk of PC mortality.