41 patients with hyperlipidemia(Serum cholesterol > or =260mg% or triglyceride> or =200mg%) were treated for 12 weeks each with either Bezafibrate(200mg t.i.d.)(n=23) or placebo(n=18) in a randomized trial. Compared with placebo, Bezafibrate was more effective in lowing total cholesterol(287+/-63 to 244+/-32 mg%, P<0.01), LDL-cholesterol(183+/-39 to 153 +/-25mg%, P<0.01) and the LDL/HDL ratio(4.7+/-2.9 to 3.4+/-1.3, P<0.05). There was also a marked reduction in serum triglyceride(307+/-295 to 218+/-167mg%, P<0.05) as well as a significant increase in HDL-cholesterol(43+/-12 to 48+/-12mg%, P<0.05). Compliance or tolerance to both Bezafibrate and placebo was good. No significant side effects except one case, who complained of mild indigestion, were observed. Therefore, Bezafibrate seemed to be effective in lowing serum total cholesterol, LDL-cholestrol, triglyceride and in increasing in HDL-cholesterol without significant side effect.