During whole body radiation therapy of children, treatment may be done in places not equipped with acceptable scavenging systems for anesthetic gases and where clinical observation of the patient may be impossible. In order to solve this problem, the authors have used a total intravenous (IV) anesthetic technique using midazolam, pancuronium, and fentanyl. With midazolam as the only hypnotic agent, the problem with scavenging is solved, and a computer simulation of the plasma concentration of midazolam is presented. A modified stethoscope for monitoring during radiation also has been developed. This anesthetic technique and the stethoscope have been used in seven children. The total IV anesthesia proved to be a useful method for children during whole body radiation. The modified stethoscope functioned very well and was a useful complement to the monitoring equipment.