Introduction: Given the importance of reducing anxiety in patients before coronary artery bypass grafting and the side effects that anxiety can have on the patient's recovery, the researchers decided to investigate the effect of aromatherapy on anxiety in patients before coronary artery bypass graft surgery. Material and Methods: This study was performed as a result of clinical experience in 2020 in Shahid Madani Hospital of Tabriz with the participation of 64 patients after coronary artery bypass graft surgery; Aromatherapy was used to reduce patients' anxiety and the results were reported. Results: Independent t-test showed that the mean anxiety score between the experimental and control groups before the intervention was not statistically significant (p= 0.984); But after the intervention, the mean anxiety in the experimental group was significantly lower than the control group (p=0.030). Also, according to the paired t-test in the control group, the anxiety scores before and after the intervention were not significantly different (p=0.509); While in the experimental group, the anxiety score after the intervention showed a significant decrease compared to before the intervention (p=0.007). Conclusion: Considering the results of this study and the positive effect of lavender scent inhalation on reducing anxiety levels in patients undergoing coronary artery bypass graft surgery in the preoperative stage.