Nigella sativa or Black seed (N. sativa L.) is traditionally used for several ailments in many Middle Eastern countries. It is an annual herbaceous plant that belongs to the Ranuculacea family with many beneficial properties as antitumor, antidiabetic, antihypertensive, antioxidative and antibacterial. This work attempted to study the effect of N. sativa seeds powder and oil on atherosclerosis in diet-induced hypercholesterolemic (HC) rabbits in comparison with simvastatin (ST). Twenty-five adult New Zealand male white rabbits, weighing 1.5-2.5 kg, were divided into five groups; normal group (NC, n = 5) and four hypercholesterolemic groups (n = 20): a positive control (PC) and three HC groups force fed diet supplemented with 1000 mg Kg(-1) body weight of N. sativa powder (NSP), 500 mg Kg(-1) body N. sativa oil (NSO) and 10 mg Kg(-1) ST for 8 weeks. Feeding HC rabbits with N. sativa either in powder or oil forms was shown to significantly reduce (P < .05) total cholesterol (TC) and low-density lipoprotein cholesterol (LDLC) levels and enhance high-density lipoprotein cholesterol (HDL) levels after treatment for 2, 4, 6 and 8 weeks compared to the PC group. Plaque formation was significantly inhibited while the intima: media ratio was significantly reduced in the NSP and NSO supplemented groups compared to the PC group. In conclusion, treatment of HC rabbits with N. sativa seeds powder or oil showed hypocholesterolemic and antiatherogenic cardioprotective properties.