Researchers have always been investigating to produce methods and drugs with least hemodynamic changes occur during induction of anesthesia and laryngoscopy in patients.Propofol and Etomidate are well‑known anesthetic agents routinely used for the induction of anesthesia for cardiac surgeries.The two drugs however have different induction characteristics.Etomidate is only unique drug with standard doses for induction of anesthesia and laryngoscopy, hemodynamic changes were not observed in patients. Despite the great advantage of lack of hemodynamic changes during anesthesia induction, Etomidate can cause inhibition of cortisol production in response to ACTH And can increase morbidity and mortality in these patients. Considering the importance and effectiveness of hemodynamic changes resulting in surgical procedures and mortality related to it and the results contradict previous studies, we need to investigate in a study to compare the propofol, diazepam and etomidate for induction of anesthesia with the least hemodynamic changes in patients with low ejection fraction.The aim of the present study is to compare the hemodynamic responses of etomidate ,propofol and diazepam during anesthesia induction, laryngoscopy and tracheal intubation in CABG surgery patients with low EF in order to find proper drug establishing more stable hemodynamic. Methods: it is double blind randomized, clinical study will be conducted for total 150 patients with low ejection fraction undergoing coronary artery bypass graft surgery. Preliminary selection of patients will be randomly. Inclusion criteria is patients with CAD and left ventricular dysfunction (EF < 35%), stable hemodynamic(SBP>90), scheduled for elective CABG surgery with CPB and no fatal dysrhytmias . Exclusion criteria included known adrenal insufficiency, chronic inflammatory diseases, history of steroid use in the preceding six months, endocrine or neurological illnesses, tracheal intubation time more than 30 seconds, sepsis, endocarditis, combined cardiac valve surgery with CABG and Bentall surgery. After approval from the institutional ethics committee and written informed consent from the patients, a total of 150 patients will be included in this study and will randomly allocated to group A and B and C (50 patients in each group) by the sealed envelope technique. Patient allocation will be performed by a nurse who was unaware of the study groups, according to numbers generated by the computer generated list. In the operating room and before induction of anesthesia, 5 cc/kg Ringer lactate will be infused for all patients via an intravenous line. Also electrocardiogram, invasive arterial blood pressure, and pulse oximeter will applied for all patients and baseline systolic and diastolic arterial blood pressure (SAP, DAP), mean arterial pressure (MAP) and heart rate (HR) will be measured and recorded for all of them.Then all patients will receive fentanyl (2μg/kg) and midazolam (0.03 mg/kg) intravenously as premedication. One minute later, patients in group A will induced with propofol(1.5 mg/kg), group B Etomidate (0.2 mg/kg) and group C Diazepam (0.3mg/kg). All drugs will receive the drugs at the same speed and within 60-90 seconds. Then, all patients will receive 1.5 mg/kg succinylcholine for muscle relaxation to facilitate intubation. One minute after succinylcholine administration, tracheal intubation will be performed. Hemodynamic variables including SAP, DAP, MAP and HR will measured immediately before and after laryngoscopy and intubation, one, two and three minutes after intubation.