The prevalence of elevated blood cholesterol in China has increased during the past several decades. We estimated the percentage of the Chinese population for whom therapeutic lifestyle changes and drug therapy to lower blood cholesterol should be considered by applying the United States' National Cholesterol Education Panel's Adult Treatment Panel III guidelines to a nationally representative sample of the Chinese population from the International Collaborative Study of Cardiovascular Disease in Asia. Serum samples were collected for 14,919 Chinese adults, 35 to 74 years old, in 2000 and 2001, after an overnight fast of > or =8 hours and their low-density lipoprotein (LDL) cholesterol level was calculated using the Freidewald equation. Using the Adult Treatment Panel III guidelines, 85.9 million Chinese adults (18.2%) should initiate therapeutic lifestyle changes to lower their LDL cholesterol and 35.0 million (7.4%) should be considered for lifestyle changes and lipid-lowering drug therapy. Of those for whom drug therapy should be considered, 4.7 million (13.4%) reported having been told they had "high cholesterol" by a healthcare provider and 1.6 million (33.7% of those aware of their high cholesterol) were receiving lipid-lowering medication-leaving 33.4 million Chinese adults with untreated elevated LDL cholesterol (95.5% of those with elevated LDL cholesterol). A 10% population-wide reduction in LDL cholesterol would reduce the number of Chinese adults who should be considered for drug therapy by 45% to 19.3 million (4.1% of adults). In conclusion, most adults in China with an elevated LDL cholesterol remain untreated.