This purpose of this study is to determine if the administration of ezetimibe and simvastatin together is more effective than simvastatin alone in lowering LDL-C levels to a goal of <100 mg/dL in patients at risk for Heart Disease.

Inclusion Criteria:

• Men and women aged 18 to 80 at risk for Heart Disease who have LDL-C levels greater than or equal to 130 mg/dL and triglyceride level less than or equal to 350 mg/dL
• Patients must be able to maintain the National Cholesterol Education Program diet throughout the course of the study

Exclusion Criteria:

• Patients are excluded from the study if their weight is less than 50% of ideal body weight, if they are pregnant or lactating, have congestive heart failure, uncontrolled heart rhythm problems or a recent heart attack, coronary artery bypass surgery, or angioplasty. Additionally, patients with poorly controlled Type 1 or 2 diabetes mellitus, kidney disease, uncontrolled endocrine or metabolic disease, are known HIV positive, and uncontrolled high blood pressure