INTRODUCTION: The preoperative evaluation and preparation is a multidisciplinary, multistep process preceding surgery, consisting of the preoperative risk assessment and the patient’s medical status optimization before surgery, with the purpose of reducing surgical morbidity and mortality. EVIDENCE ACQUISITION: Preoperative evaluation includes taking a medical history and performing routine diagnostic tests. In a pre- anesthetic evaluation, the airway is assessed, commonly by the LEMON approach, in order to predict potential problems that may be encountered during intubation, as well as in order to estimate perioperative risk using ASA classification. Although the patient’s preoperative preparation depends on the type of surgery, preoperative fasting is important in any surgical procedure, due to anesthesia reasons. To reduce surgical infections, antibiotic prophylaxis is used. EVIDENCE SYNTHESIS: Preoperative evaluation is a dynamic process that implies a thoughtful reconsideration of all gathered information, with the purposes of meeting both patients’ needs and the requirements of surgery and anesthesia. It is an opportunity to evaluate the acute illness and to optimize chronic disease, as well as to assess perioperative risk. Medical history and physical examination remain the strongest predictors of the perioperative risk. According to recent studies, preoperative routine tests in an apparently healthy patient, are neither beneficial nor cost-effective. CONCLUSIONS: Preoperative evaluation and preparation protocols are used in order to reduce the morbidity and mortality of the patients undergoing surgery. Following the guidelines for each step of the protocol and providing evaluation and care for the patients based on their needs, lead to desired surgical outcomes.