BACKGROUND: The randomized double-blind parallel group trial, INPRACTICE, demonstrated a significant benefit of ezetimibe co-administration with simvastain 10/40 mg in patients achieving LDL-C targets of < 2 mmol/L, compared to atorvastatin 40 mg and rosuvastatin 5-10 mg (according to UK label) OBJECTIVES: : To estimate the cost of treatment for achieving 1 % LDL-C reduction and the cost of getting a patient to LDL-C target of < 2 mmol/L with ezetimibe co-administered with simvastatin, compared to atorvastatin and rosuvastatin. METHODS:   Following a 6-week run-in period on 40mg simvastatin, patients were randomized to receive ezetimibe/simvastatin 10/40mg, atorvastatin 40mg or rosuvastatin 5-10mg for 6 weeks. The total treatment cost for the trial period was estimated. A post-hoc analysis of the trial participants was conducted to compare the treatment cost per patient achieving LDL-C target of < 2mmol/L between the three comparator treatments. The cost of generic simvastatin 40mg was assumed to be £1.37 for a 28 day treatment (BNF). RESULTS: At the end of the 6 week trial period, the treatment cost per 1% reduction in LDL-C was estimated to be £1.58 (95% CI: £1.42-£1.79) for ezetimibe co-administered with simvastatin. The corresponding treatment costs were £3.33 (£2.64-£4.51) and £9.02 (£4.59-£450.75) for atorvastatin and rosuvastatin, respectively. Cost per patient achieving the LDL-C target of < 2 mmol/L was £61.49 (95% CI: £56.66-£67.22) for ezetimibe co-administered with simvastatin compared to £101.84 (£87.69-£121.42) for atorvastatin and £155.06 (£122.54-£211.12) for rosuvastatin. CONCLUSIONS: Co-administration of ezetimibe with simvastatin 40mg is a cost efficient way of reducing LDL-C compared to atorvastatin 40mg or rosuvastatin 5-10mg monotherapy regimen.