Correction of cardiovascular risk factors is of particular significance in a high-risk population, such as that of diabetic patients. This paper reports the effects of one-month administration of 400 mg/day Bezafibrate (BZF), followed by a two-month wash-out and one-month administration of 500 mg/day Acipimox (APX) or vice versa in a random order in 16 Type 2 diabetic patients with diet-resistant hyperlipidaemia and in good metabolic control (HbA1c < 8 %), on plasma fibrinogen and on their lipid pattern. Metabolic control displayed a nonsignificant improvement (HbA1c) during both treatments (stable body weight). Both BZF and APX produced a 14 % decrease in total CHOL (p < 0.01), whereas BZF was more effective in reducing triglycerides (tg) (- 37 % vs - 15 %). The marked BZF-induced Tg reduction was associated with a proportional decerase in Apo B, while an increase in total HDL-, HDL2 and HDL3-CHOL, together with a significant increase in Apo AI, was observed. APX treatment resulted in a HDL2-CHOL increase only (+ 29 %). Both drugs reduced VLDL-CHOL (BZF - 37 % ; APX - 15 %) and VLDL-Tg (- 56 % and - 34 %). In BZF treated patients Apo CIII fell indicating a possible reduction of specific inhibition of lipoprotein lipase activity, while APX affected both Apo CII (+ 23 %) and Apo CIII (- 26 %) and led to a 62 % Apo CII/CIII ratio increase. BZF alone led to a significant 25 % decrease in plasma fibrinogen (from 415 +/- 14.3 to 312.1 +/- 18.1 SEM mg/dl, p < 0.001). Its action on the hemorheological-coagulative component could thus serve as an additional preventive tool in the treatment of both dyslipidaemic and hyperfibrinogenaemic diabetic patients. The results obtained with both drugs indicate their usefulness in the pharmacological treatment of hyperlipidaemia of diabetes mellitus, using either the more selective action of APX or the broader effect of BZF, as required. BZF seems particularly indicated when hyperfibrinogenaemia or haemorheological alterations are also present.