SummaryA double blind clinical trial of one year duration was performed to compare the activity of halofenate (1 000 mg once a day) and of clofibrate (1 000 mg twice a day) on plasma levels of cholesterol, triglycerides and uric acid in 20 hyperlipidaemic patients.Statistical analysis showed that clofibrate provokes a significant decrease of cholesterol and triglycerides, a slight (p>0.05) increase of uric acid. Halofenate did not influence significantly any of three levels. Noteworthy is the decrease in uric acid,.caused by halofenate (18 % after 24 weeks -p<0.05), although the basal uric acid values were normal.Clinically both drugs were well tolerated. Alkaline phosphatase levels significantly decreased during treatment with clofibrate.