Background: Anxiety is an emotional state characterized by apprehension and fear resulting from anticipation of a threatening event.Objectives: The present study aimed to analyze the incidence and level of preoperative Anxiety in the patients scheduled for cardiac surgery by using a Visual Analogue Scale for Anxiety (VAS-A) and Amsterdam Preoperative Anxiety and Information Scale (APAIS) and to identify the influencing clinical factors.Patients and Methods: This prospective, longitudinal study was performed on 300 cardiac surgery patients in a single university hospital. The patients were assessed regarding their preoperative Anxiety level using VAS-A, APAIS, and a set of specific Anxiety-related questions. Their demographic features as well as their anesthetic and surgical characteristics (ASA physical status, EuroSCORE, preoperative Length of Stay (LoS), and surgical history) were recorded, as well. Then, one-way ANOVA and t-test were applied along with odds ratio for risk assessment.Results: According to the results, 94% of the patients presented preoperative Anxiety, with 37% developing high Anxiety (VAS-A³7). Preoperative LoS>2 days was the only significant risk factor for preoperative Anxiety (odds ratio=2.5, CI 95%, 1.3 - 5.1, P=0.009). Besides, a positive correlation was found between Anxiety level (APAISa) and requirement of knowledge (APAISk). APAISa and APAISk scores were greater for surgery than for anesthesia. Moreover, the results showed that the most common anxieties resulted from the operation, waiting for surgery, not knowing what is happening, postoperative pain, awareness during anesthesia, and not awakening from anesthesia.Conclusions: APAIS and VAS-A provided a quantitative assessment of Anxiety and a specific qualitative questionnaire for preoperative Anxiety in cardiac surgery. According to the results, preoperative LoS>2 days and lack of information related to surgery were the risk factors for high Anxiety levels.