The relevance of low-density lipoprotein cholesterol (LDL-C) or non-high-density lipoprotein cholesterol (non-HDL-C) goals for primary prevention of atherosclerotic cardiovascular disease (ASCVD) among patients with diabetes was assessed. This retrospective cohort study included patients with type 2 diabetes, age 21 to 90years, taking statins, with no history of ASCVD as of January 1, 2006, in Kaiser Permanente Northern California, an integrated healthcare delivery system. Multivariate cox models were utilized to estimate hazard ratios (HRs) for incident ASCVD events by achieved LDL-C and non-HDL-C levels with adjustment for potential confounders. Incident ASCVD events were defined as a composite of myocardial infarction, ischemic stroke, or coronary heart disease death. A cohort of 62,428 patients, with mean age of 64.1years, 46.9% women, and mean follow-up of 6.0 years, was identified. After adjustment, the risk of incident ASCVD for these statin-treated patients was monotonically lower with decreasing achieved LDL-C levels (p<0.0001 for trend) and non-HDL-C levels (p <0.0001 for trend). Relative to achieved LDL-C ≥130 mg/dl, LDL-C <50 mg/dl had HR = 0.58 (95% confidence interval 0.49 to 0.69). Relative to achieved non-HDL-C ≥160mg/dl, non-HDL-C <80 mg/dl had HR = 0.59 (95% confidence interval 0.51 to 0.68). In a large cohort of statin-treated diabetic patients without ASCVD, a monotonically lower risk of incident ASCVD events was associated with lower achieved lipid levels. These findings support the use of LDL-C ornon-HDL-C treatment goals for ASCVD primary prevention in diabetic patients.