Objectives: There is increasing evidence that intake of sour tea (Hibiscus sabdariffa) has hypoglycemic and hypolipidemic effects and may benefit patients suffering from metabolic disorders such as diabetes. The objective of the present study was to investigate the hypolipidemic effects of sour tea in patients with diabetes and compare them with those of black tea. Design: In this sequential randomized controlled clinical trial, 60 patients with diabetes were recruited and randomly assigned into two groups: sour tea (ST) and black tea (BT). They were instructed to consume sour tea or black tea two times a day for 1 month. Outcome measures: Fasting blood samples were taken at the beginning and at the end of the study for evaluation of lipids, lipoproteins, and apoproteins. Results: Fifty-three (53) patients concluded the study. In the ST group, mean of high-density lipoprotein-cholesterol (HDLc) increased significantly (p=0.002) at the end of the study, whereas changes in apolipoprotein-A1, and lipoprotein (a) were not significant. Also, a significant decrease in the mean of total cholesterol, low density lipoprotein-cholesterol, triglycerides, and Apo-B100 were seen in this group. In the BT group, only HDLc showed significant change (p=0.002) at the end of the study and changes in the other measures were not statistically significant. Conclusions: The results of the present study showed that ST has a significant effect on blood lipid profile in patients with diabetes.