Hysteroscopic surgery has gained in popularity and has become the method of choice for diagnostic and therapeutic interventions of intrauterine pathology. Advantages consist of short operating time, rapid postoperative recovery, and low morbidity. However, there are concerns about the potential serious complications that can occur, such as venous air and gas embolism. These are rare but hazardous complications, which can occur in all surgical procedures. In hysteroscopic surgery, large uterine veins may be exposed and are, therefore, a point of entry for gas or air. A number of fatal and nonfatal cases have been described as case reports. Although awareness for air and gas embolism is raised this way, proper guidelines as to how to reduce the risk of venous gas or air embolism are lacking. The pathophysiologic difference between gas and air embolism is described herein because composition of the gases differs as does their physiologic effects. A gas embolism is likely to be derived from electrosurgical vapors whereas air embolism seems to arise from improper purging of lines or reinsertion of hysteroscopic instruments. Treatment regimens must, therefore, be designed to address the specific gases involved. Signs and symptoms of these different embolisms are described, as early detection and intervention are crucial for survival. Furthermore, we provide guidelines for operating department personnel, surgeons, and anesthesiologists to reduce the risk of venous gas or air embolism during hysteroscopic procedures. Potential complications of these procedures may be prevented this way.