BACKGROUND: Statins are lipid-lowering drugs that reduce the risk of cardiovascular events in patients with diabetes. OBJECTIVES: The objective of this study was to determine whether statin treatment for primary prevention in newly diagnosed type 2 diabetes is cost-effective, taking nonadherence, baseline risk, and age into account. METHODS: A cost-effectiveness analysis was performed by using a Markov model with a time horizon of 10 years. The baseline 10-year cardiovascular risk was estimated in a Dutch population of primary prevention patients with newly diagnosed diabetes from the Groningen Initiative to Analyse Type 2 Diabetes Treatment (GIANTT) database, using the United Kingdom Prospective Diabetes Study risk engine. Statin adherence was measured as pill days covered in the IADB.nl pharmacy research database. Cost-effectiveness was measured in costs per quality-adjusted life-year (QALY) from the health care payers' perspective. RESULTS: For an average patient aged 60 years, the base case, statin treatment was highly cost-effective at €2245 per QALY. Favorable cost-effectiveness was robust in sensitivity analysis. Differences in age and 10-year cardiovascular risk showed large differences in cost-effectiveness from almost €100,000 per QALY to almost being cost saving. Treating all patients younger than 45 years at diabetes diagnosis was not cost-effective (weighted cost-effectiveness of almost €60,000 per QALY). CONCLUSIONS: Despite the nonadherence levels observed in actual practice, statin treatment is cost-effective for primary prevention in patients newly diagnosed with type 2 diabetes. Because of large differences in cost-effectiveness according to different risk and age groups, the efficiency of the treatment could be increased by targeting patients with relatively higher cardiovascular risk and higher ages.