Background There are limited data on low-density lipoprotein cholesterol (LDL-C) goal achievement per the 2019 European Society of Cardiology/European Atherosclerosis Society dyslipidemia management guidelines and its impact on long-term outcomes in patients undergoing coronary artery bypass grafting (CABG). We investigated the association between LDL-C levels attained 1 year after CABG and the long-term outcomes. Methods and Results A total of 2072 patients diagnosed with multivessel coronary artery disease and undergoing CABG between 2011 and 2020 were included. Patients were categorized by lipid levels at 1 year after CABG, and the occurrence of major adverse cardiovascular and cerebrovascular events (MACCEs) was evaluated. The goal of LDL-C <1.40 mmol/L was attained in only 310 patients (14.9%). During a mean follow-up of 4.2 years after the index 1-year assessment, 25.0% of the patients experienced MACCEs. Multivariable-adjusted hazard ratios (95% CIs) for MACCEs, cardiac death, nonfatal myocardial infarction, nonfatal stroke, revascularization, and cardiac rehospitalization were 1.94 (1.41-2.67), 2.27 (1.29-3.99), 2.45 (1.55-3.88), 1.17 (0.63-2.21), 2.47 (1.31-4.66), and 1.87 (1.19-2.95), respectively, in patients with LDL-C ≥2.60 mmol/L, compared with patients with LDL-C <1.40 mmol/L. The LDL-C levels at 1-year post-CABG were independently associated with long-term MACCEs. Conclusions This retrospective analysis demonstrates that lipid goals are not attained in the vast majority of patients at 1 year after CABG, which is independently associated with the increased risk of long-term MACCEs. Further prospective, multicenter studies are warranted to validate if intensive lipid management could improve the outcomes of patients undergoing CABG.