We examined the effects of intensive statin therapy in patients with acute coronary syndromes (ACSs) and previous coronary artery bypass graft surgery (CABG) participating in the Pravastatin or Atorvastatin Evaluation and Infection Therapy-Thrombolysis In Myocardial Infarction 22 (PROVE-IT TIMI 22) and the Aggrastat to Zocor (A to Z) trials. Of the 8,655 patients enrolled in PROVE IT-TIMI 22 or A to Z, 640 (7.4%) had undergone CABG before enrollment. After a median follow-up of 2 years, compared with patients without previous CABG, those with previous CABG had a higher risk of cardiovascular death (6.2% vs 2.8%), myocardial infarction (14.2% vs 6.6%), and readmission for ACS (7.9% vs 4.4%, p <0.001 for all comparisons) but a lower rate of repeat coronary revascularization (22.7% vs 26.9%, p = 0.01). Compared with moderate statin therapy, intensive statin therapy appeared to decrease the composite of cardiovascular death, myocardial infarction, stoke, and readmission for an ACS (A to Z primary end point) to a similar extent in patients with (26.1% vs 21.6%, hazard ratio 0.84, p = 0.27) and without (13.9% vs 12.0%, hazard ratio 0.86, p = 0.016) previous CABG, although the decrease was not statistically significant in the previous CABG group, likely due to the small number of patients with previous CABG. In conclusion, compared with patients with ACS without previous CABG, those with previous CABG have a higher risk for adverse cardiac events and may derive similar benefit from intensive statin therapy.