Twenty-eight children between the ages of 9 weeks and 17 years have been examined by nuclear magnetic resonance (NMR) imaging. Twelve had images of the brain made, the remainder having either chest, abdomen or pelvis examined. NMR imaging does not utilize ionising radiation to produce an image. Instead, it relies on measuring the response of hydrogen protons to an applied radiofrequency pulse and is a safe non-invasive imaging technique. In all cases studied NMR gave a clear demonstration of the gross anatomy as well as physiological and pathological information. Since NMR does not employ ionising radiation to produce its images, it is believed that it should become the method of choice for the evaluation of the child with suspected intracranial pathology, chronic lung disease, and suspected intra-abdominal or pelvic mass lesions. The unique information about proton concentration and proton spin-lattice relaxation time should prove to be useful in developmental research.