Summary: The conduction responses of semiconducting single-walled carbon nanotube (SWCNT) films irradiated by 6 and 15 MV X-rays were evaluated. Results indicate that the average resistance–dose rate relations of the SWCNT network are quasi-linear and can be used for dosimetry measurements in medical radiation applications. The dynamic responses exhibit fluctuations which reveal an intrinsic feature of SWCNT networks due to the large number of interconnections between individual SWCNTs.