Background: Hospitalization and surgery are crucial adverse life events that lead to considerable anxiety in patients. Objectives: The present study aimed to investigate stressors after coronary artery bypass graft surgery and identify stressors that predict anxiety. Patients and Methods: This is a descriptive-analytical study that uses a non-random convenience sampling method on patients undergoing coronary artery bypass graft surgery at the cardiac surgery intensive care unit of Fatemeh Zahra Cardiac center in Sari, Iran. A total of 186 patients completed the post-surgical stressors questionnaire and the Spielberger State-Trait Anxiety Inventory on postoperative days 2 or 3 in the cardiac surgery intensive care unit. Data were analyzed using descriptive statistics including frequencies, means, and standard deviations. The Mann-Whitney U test was used to determine the relationship between the observed variables, and the logistic regression model was used to identify the relationship between stressors and anxiety after-surgery. Results: Post-surgical anxiety predictors included insufficient sleep during hospitalization (Odds ratio [OR]: 5.42; 95% confidence interval [CI]: 1.46 - 20.00; P = 0.010), treatment not explained to the patient by the nurse (OR: 4.83; 95% CI: 1.82 - 12.84; P = 0.002), being away from family members (OR: 3.88; 95% CI: 1.46 - 10.26; P = 0.006), presence of a chest tube (OR: 3.27; 95% CI: 1.83 - 5.84; P = 0.000), and pain in any part of the body (OR: 1.95; 95% CI: 1.06 - 3.58; P = 0.031). Conclusions: Physical or physiological and psychological stressors impose greater stress and are predictors of anxiety. When preparing their nursing care plan, nurses should consider these stressors that affect anxiety levels in patients undergoing CABG surgery and those hospitalized in intensive care units.