Metronidazole, a synthetic derivative of tile nitroimidazole class, is a known antibacterial and antiprotozoal agent. Following an anecdotal observation of hypolipidemic effect of metronidazole, a randomized open trial of 250 mg three times daily was conducted in 30 subjects. This open label crossover trial was performed in three stages-14 days each-as challenge, wash out and re-challenge on 30 subjects, including six male and 24 female in the age limits of 40 to 73 years (mean 58.7+/-10.6 years). Results of this trial revealed that metronidazole 750 mg daily in divided doses for 14 days decreased the average of total blood cholesterol in 30 cases by 46+/-27 mg/dl (14.6%, P=0.025) and LDL cholesterol by 39+/-28 mg/dl (22%, P=0.005). Decrease in total and LDL cholesterol and increase in HDL cholesterol by 3.8+/-4.1 mg/dl also accompanied fall of triglyceride level cases by 68+/-13 mg/dl. This study suggests that metronidazole or its derivatives may form a new class of lipid lowering compounds.