The aim of this study was to evaluate the effects of rosuvastatin and fenofibrate alone and in combination in type 2 diabetes associated with combined hyperlipidaemia. A total of 216 patients with total cholesterol >/=200 mg/dl (>/=5.17 mmol/l) and triglycerides >/=200 and <800 mg/dl (>/=2.26 and <9.03 mmol/l) were randomised to one of two placebo groups, rosuvastatin 5 mg or rosuvastatin 10 mg for 6 weeks (fixed-dose phase). During the subsequent 18-week dose-titration phase, one placebo group received titrated rosuvastatin 10, 20 and 40 mg (placebo/rosuvastatin); one placebo group received titrated fenofibrate 67 mg once, twice and three times daily (placebo/fenofibrate); and patients receiving 5 or 10 mg rosuvastatin received titrated fenofibrate as above (rosuvastatin 5mg/fenofibrate and rosuvastatin 10 mg/fenofibrate groups). Doses were increased at 6-week intervals if low-density lipoprotein (LDL) cholesterol remained >50 mg/dl (>1.3 mmol/l). At 24 weeks, the placebo/rosuvastatin group and placebo per fenofibrate group had triglyceride reductions of 30.3% versus 33.6%, respectively (P = NS), and LDL cholesterol was reduced by 46.7% in the rosuvastatin group and increased by 0.7% in the fenofibrate group (P < 0.001). The triglyceride reduction in the rosuvastatin 10 mg/fenofibrate group (47.1%) was significantly greater than in the placebo/rosuvastatin group (P = 0.001), with no significant differences in other lipid measures found between these two groups. No significant differences in effect on high-density lipoprotein (HDL) were observed among treatment groups. In the fixed-dose phase, rosuvastatin 5 and 10 mg reduced triglycerides by 24.5 and 29.5%, respectively, and decreased LDL cholesterol by 40.7 and 45.8%, respectively. All treatments were well tolerated. These results indicated that rosuvastatin produces marked reductions in triglycerides and LDL cholesterol when used alone or in combination with fenofibrate in type 2 diabetes patients with elevated cholesterol and triglyceride levels and may constitute a valuable treatment option in the diabetic population.