High intensity focused ultrasound (HIFU) is a treatment modality for tissue ablation with an expanding range of indications. It is helpful to understand its basic principles, the physiological changes induced, and the pathophysiology of the patient groups undergoing HIFU. HIFU is usually performed in a radiology suite, and requires co-ordinated efforts between the radiologist/surgeon and anaesthetist during ablation therapy to enhance accuracy of treatment and patient safety. Planning of the equipment, ventilation strategies and drugs needed during the procedure would reduce potential anaesthetic and procedure-related complications.