Abstract Temperature rises generated by diagnostic ultrasound from a modified commercial system (Sonos 1000 Hewlett Packard) in a transcranial phantom that consists of human temporal bone and tissue-mimicking material are measured. Significant temperature rises were found at the external and internal temporal bone surfaces. The experimental results are compared with cranial thermal indices (TIC) developed by the American Institute of Ultrasound in Medicine and the National Electrical Manufacturers Association for various modes. For all the modes compared, TIC underestimated temperature rise at the external temporal bone surface. The differences between the data and temperature rises predicted by TIC can be attributed to transducer surface heating.