Abstract: Atherosclerosis is the most common cause of mortality worldwide with hyperlipidemia as an important cause. Finding suitable and effective treatment which can both control the level of blood lipids and solution. Metronidazole is the drug that is only used as an antibacterial and antiprotozoal agent. Researcher have found that oral dose of 750 mg/day has a suitable absorption, is widely distributed in the tissues and reaches to a serum level of 4-6 g m L ¹. Despite its suitable efficiency, a few clinical trial have been conducted in this regard. This study was designed as such to examine effect of Metronidazole on lowering serum lipids. The present research was performed as a clinical trial without control, on 150 patients. The tests of LFT, BUN creatinin, SGOT and SGPT were done on these subjects. Metronidazole was given with a daily dose of 750 mg for 2 weeks. 100 of these patients who had less complaint continued their drug consumption for another 14 days. Lipid parameters such as serum total lipid, total cholesterol and triglyceride were measured in both groups. The data were collected and analyzed with students t-test using SPSS software. Measuring the serum level of lipids indicated that the mean total serum lipid and total cholesterol decreased significantly compared to their levels before taking the drug (p<0.05). The findings also showed a similar decrease in serum TG level (p<0.05). In the patients who continued the drug consumption, the serum level of lipids under study showed more decrease compare to first 2 week significantly (p<0.01). Metronidazle can be be suggested a probable candidate as a new drug in the shor life treatment of hyperlipidemia. As the drug for this disorder should be used for a long time, therefore it requires more investigations.