Preoxygenation and apneic oxygenation (AO) are essential in airway management and prevention of low saturation during anesthesia and are very important for patient safety and quality. Preventing and reducing severe complications in airway management is a challenging and essential task for anesthesiologists. Good quality and preoxygenation are critical in airway management and vital prerequisites in AO. At the same time, preoxygenation increases “the safe apnea time” before desaturation, and AO significantly reduces the incidence of hypoxemia during endotracheal intubation. Inappropriate and inadequate preoxygenation, obesity, pregnancy, airway obstruction, pulmonary shunt, pediatric patients, and critical illness are important risk factors for short apnea windows. Face mask, bag-valve mask, venturi mask, nasal cannula, nasopharyngeal catheter, double blade laryngoscopes, transtracheal endobronchial catheters, and high-flow nasal cannula (HFNC) oxygenation by applying low-flow oxygen, or high-flow oxygen are the most commonly used systems in preoxygenation. Regardless of the method in anesthesia practice, preoxygenation and AO are very important in reducing hypoxemia, mortality, and morbidity. Herein, our aim in this review is to emphasize the importance of preoxygenation and AO in our anesthesia practice.