With the growth and expansion of mouse and rat transgenic models in recent years, the demand for surgically altered models mimicking human diseases is growing at an amazing rate. Surgical procedures are performed under anesthesia, and this has a profound effect on physiological systems and makes many protective mechanisms ineffective. Therefore it is critical to manage anesthetic depth so as to minimize adverse effects such as depression of respiration, and disruption of the cardiovascular system and thermoregulation. Physiological monitoring is an integral part of overall peri-operative care to ensure animal safety, and allow for control of physiological functions through the use of drugs, instrumentation, and the anesthetist's own senses. Additionally, the 8th Edition of the Guide for the Care and Use of Laboratory Animals incorporated a new subsection on intraoperative monitoring, which underlines the importance of physiological monitoring and stresses its importance during anesthesia. During this session, veterinary technicians, veterinarians, scientists, trainers and IACUC personnel will learn about the hazards of not performing physiological monitoring, understand how anesthesia can be refined with the use of physiological monitoring. Attendees will also be able to select appropriate, adequate and reliable equipment for physiological monitoring of rodents and learn how it can significantly increase the efficiency of anesthesia and prevent the over-anesthetizing of rodents.