Intensive statin therapy is a central component of secondary prevention after acute myocardial infarction (AMI), particularly among high-risk patients, such as those with diabetes mellitus (DM). However, the frequency and predictors of intensive statin therapy use after AMI among patients with DM have not been described. We examined patterns of intensive statin therapy use (defined as a statin with expected low-density lipoprotein cholesterol lowering of >50%) at discharge among patients with AMI with known DM enrolled in a 24-site US registry. Predictors of intensive statin therapy use were evaluated using multivariable hierarchical Poisson regression models. Among 1,300 patients with DM after AMI, 22% were prescribed intensive statin therapy at hospital discharge. In multivariable models, ST-elevation AMI (risk ratio [RR] 1.48, 95% confidence interval [CI] 1.29 to 1.70), insurance for medications (RR 1.28, 95% CI 1.00 to 1.63), and higher low-density lipoprotein cholesterol levels (RR 1.05 per 1 mg/dl, 95% CI 1.02 to 1.07) were independent predictors of intensive statin therapy, whereas higher Global Registry of Acute Coronary Events scores were associated with lower rates of intensive statin therapy (RR 0.94 per 10 points, 95% CI 0.91 to 0.98). In conclusion, only 1 in 5 patients with DM was prescribed intensive statin therapy at discharge after an AMI. Predictors of intensive statin therapy use suggest important opportunities to improve quality of care in this patient population.