Background To assess the short-term effects of a micronised formulation of fenofibrate on lipids, lipoproteins and their composition, reflecting an atherogenic lipoprotein phenotype (ALP), in patients with stable Type 2 diabetes. Methods Thirty-two (18 male, 14 female) patients with Type 2 diabetes were randomised to a double-blind, placebo-controlled parallel group study after a 4-week diet run-in phase to a 12-week treatment period with either daily micronised fenofibrate 200 mg (Lipantil Micro®) or placebo. Results Baseline mean lipid and lipoproteins were similar in both groups: total cholesterol (TC) 7.5 mmol/l, serum triglyceride (TG) 3.1 mmol/l, HDL-cholesterol (HDL-c) 1.2 mmol/l, LDL-cholesterol (LDL-c) 4.7 mmol/l, and a predominance (52%) of small dense LDL-III at concentration of 192 mg lipoprotein/100 ml, reflecting an ALP. Treatment with micronised fenofibrate resulted in significant changes in TC (−17%, p<0.001), serum TG (−44%, p<0.05), HDL-c (+20%, p<0.01), LDL-c (−22%, p<0.001), apo-B (−18%, p<0.05) and alterations in LDL subfraction masses (LDL-I +64%, p<0.05; LDL-II +53%, p<0.05; LDL-III −51%, p<0.001) resulting in LDL-III comprising 28% of total LDL (p<0.001). In the placebo group the only significant changes were in TG (+21%, p<0.05) and apo-B (+9%, p<0.05). Conclusions Micronised fenofibrate therapy in patients with Type 2 diabetes improved an establisheded ALP resulting in a more favourable lipid and LDL subfraction profile. The long-term clinical implications of these changes await the results of the major intervention trials of lipid modification in Type 2 diabetes. Copyright © 1999 John Wiley & Sons, Ltd.