This study aims to compare the incidence of intra & postoperative anesthetic adverse events between Waterpipe tobacco smokers and non-smokers regarding hemodynamics, oxygen saturation, levels of carboxyhemoglobin, peak airway pressure, end-tidal CO2, perioperative adverse events in the form of, ( desaturation, laryngospasm, bronchospasm, breath holding ,time to recovery after discontinuation of anesthesia, need of oxygen supplementation in the recovery room). incidence of major postoperative respiratory complications(need for mechanical ventilation, ARDS, pneumonia, pulmonary edema ,respiratory failure).50 patients divided into two groups, study group was waterpipe smokers and control group who was non- smokers .all underwent elective surgery under standard general anesthesia, all was ASAI and ASA