This experimental study had approved by animal ethics of Central Drug Research Institute, Lucknow, and had undertaken to evaluate the antidyslipidemic and anti-oxidant activities of Nigella Sativa (N. Sativa), Hindi name Kalonji seeds extract in two models of hyperlipidemia. 1-triton and 2cholesterol-rich high-fat diet (HFD) induced hyperlipidemia. N. Sativa and Gemfibrogil were macerated with 2% aqueous gum acacia, and the suspension had fed orally to rats at a dose of 500 mg/Kg (b.w.p.o.) respectively. Serum lipids were found to be lowered by N. Sativa in triton induced hyperlipidemia. On the other hand chronic feeding of N. Sativa extracts to rats in cholesterol-rich high fat diet-induced hyperlipidemia for 30 days caused lowering in lipid and apoprotein levels of β-lipoproteins followed by an increase in lipid and apoprotein levels of α lipoproteins. The results of the present study also demonstrate that N. Sativa seeds extract repaired hepatic lipid synthesis, increased fecal bile acid excretion, and increased plasma LCAT activity in rats. Furthermore, N. Sativa seeds extract (100 to 400 µg/ml) inhibited the in vitro generation of superoxide anions and hydroxyl radicals in both enzymatic and non-enzymatic systems in a concentration-dependent manner. INTRODUCTION: Nigella sativa (N. sativa) black caraway, also known as black cumin, nigella, kalojeere, and kalonji) is an annual flowering plant in the family Ranunculaceae, native to south and southwest Asia. N. sativa grows to 20-30 cm (7.9-11.8 in) tall, with finely divided, linear (but not thread-like) leaves. The flowers are delicate and usually colored pale blue and white, with five to ten petals.