Objective: Psychological support for patients has been paid currently attention to and implemented in many medical facilities. The study aims to describe preoperative anxiety and the need for psychological support among patients with thyroid surgery and related factors. Subjects and method: A cross-sectional descriptive design was used with a convenience sample of 197 patients at the National Hospital of Endocrinology with thyroid surgery from April to June 2022. Results: The results indicated that 71.6% of patients had mild anxiety, 16.2% of patients had moderate anxiety, 11.7% of patients had no anxiety, and 0.5% of patients had severe anxiety. Common anxieties of patients undergoing thyroid surgery were postoperative complications (65%), postoperative pain (58.4%), unconsciousness after anesthesia, or surgery (46.7%), thyroid tissue remaining after surgery (44.2%), and death of anesthesia and surgery (41.1%). The average score of the need for social support was 24.02 (SD 6.01) of which family support was 12.88 (SD 3.93), and medical staff’s support was 11.14 (SD 2.73). 43.7% of patients had high support needs, 39.1% of patients had medium support needs, and 17.3% of patients had low support needs. Factors associated with patients’ anxiety included age, education level, marital status, waiting time for surgery, number of caregivers during the hospital stay, health insurance, cancer diagnosis, previous surgical history, chronic comorbidities, history of Covid19, number of Covid - 19 vaccine shots, and psychological support needs. Conclusion: The nurses should implement interventions to reduce anxiety before surgery for patients such as shortening the waiting time for surgery, regularly listening to the patient’s opinion, and consulting relevant information about the surgery.