X-ray detectors have been fabricated from a range of commercially-available chemical vapour deposition (CVD) diamond. They have been packaged and tested in a clinical environment, using clinical apparatus and following clinical procedures: 6 MV linear accelerator, solid water phantom, dosimeter. Some devices exhibited highly desirable characteristics, such as negligible dark currents (sub-pA), low priming doses (few Gy) and high specific sensitivities (up to 586 nC Gy-1 mm-3), demonstrating the potential of these devices as simple-to-use, small size, tissue-equivalent, sensitive x-ray dosimeters. The performance of such devices in clinical applications, such as beam profiling (both depth and off-axis) is currently in progress.