The extent to which atorvastatin treatment affects LDL size, LDL subfraction levels and remnant-like particle cholesterol (RLP-C) was determined in type 2 diabetes. We also compared LDL size and RLP-C in relation to guideline cut-off values for LDL cholesterol, non-HDL cholesterol and apolipoprotein (apo) B. Changes in LDL size and RLP-C were determined in fasting plasma from type 2 diabetic patients after 30 weeks administration of atorvastatin (10 mg daily, n=65; 80 mg daily, n=62) or placebo (n=58). LDL subfraction cholesterol was measured in 74 participants. Atorvastatin lowered LDL cholesterol, non-HDL cholesterol, triglycerides, apo B and RLP-C (P<0.001 for all at each dose) and LDL mean peak particle diameter remained unchanged. Atorvastatin treatment decreased cholesterol concentrations in all LDL subfractions (P<0.001 for each dose). RLP-C at follow-up was lower in those patients achieving the non-HDL cholesterol or the apo B guideline targets (P<0.01), but the LDL cholesterol cut-off value failed to discriminate. In conclusion, atorvastatin lowers fasting RLP-C and LDL subfraction cholesterol in diabetes. The proposed guideline cut-off levels for non-HDL cholesterol and apo B may be superior to the LDL cholesterol target in discriminating between higher and lower RLP-C levels.