Background: It is a known fact that altered thyroid state is associated with cardiometabolic disturbances. Raised TNF-α and lipid peroxidation have also been reported to be involved in the pathogenesis of cardiometabolic disorders. Aim: The present study evaluates the effect of dysthyroidism on cardiac TNF-α and lipid peroxidation, and whether the effect is estradiol-dependent. Methods: Male white New Zealand rabbits were randomized into three groups; control, carbimazole-induced hypothyroidism, and levothyroxine-induced hyperthyroidism. Results: Dysthyroidism led to altered glucose metabolism and dyslipidaemia with elevated LDL, TNF-α, and MDA. There was also decreased HDL, GSH, catalase, and 17β-estradiol. Serum electrolytes and hemorheological variables were not significantly affected. Conclusion: These findings demonstrate that dysthyroidism-induced cardiometabolic disturbance is associated with elevated cardiac TNF-α and oxidative stress via an estradiol-dependent mechanism.