Background: this study aimed to illustrate the protective effect of red cabbage extract against hyperthyroidism induced by L-thyroxin in male albino rats. Materials and methods: Eighteen animals were divided randomly into three groups. Group A: healthy rats, Group B:   normal rats were subcutaneous  injected with 500 µg/kg body weight/day L-thyroxin once daily for two weeks to induce hyperthyroidism and group C: hyperthyroid rats received red cabbage extract. At the end of the experiment, blood samples were collected for biochemical analysis. Results: hyperthyroid rats induced by L-thyroxin had significant decrease (P<0.05) in serum levels of triodothyronine (T3), thyroxin (T4), protein profile, lipid profile (TC, HDL) as well as a significant increase in kidney function test (BUN, uric acid), in liver enzymes (ALP, ALT), and a significant decrease in TSH, TG, VLDL compared to the normal control group. Oral administration of red cabbage extract ameliorated most of the tested parameters.