The therapeutic use of polyene antibiotic amphotericin B is known to produce a number of toxic side effects such as fever, chills, nausea, vomiting, headache and renal dysfunction with associated anoxia, hypoxalamine, nephrotoxicity including myocardial toxicity. Amphotericin B associated cellular toxicity in part has been shown to be due to lipid peroxide damage in many experimental studies. Recognition of nitric oxide (NO) as the chemical entity of endothelium-derived factor (EDRF) has renewed the interest of the scientific community in the last decade and NO was labeled as "Molecule of the year" 1992 and further as "Molecule of the Millennium" In the cardiovascular system NO exert negative inotropic and negative chronotropic effect on cardiac muscle cells, it regulates beat-to-beat regulation of cardiac function. NO regulates blood flow and pressure and potent inhibitor of platelet aggression. In view of the toxic side effects exerted by Amphotericin B and physiological roles assigned to NO, present study examined the in vivo effect of selected doses of Amphotericin B on NO pathway parameters in animal Albino rat model.