Background: Modern medical imaging is represented by a wide range of modalities such as conventional X-Ray, Computed Tomography, Magnetic Resonance Imaging, and Nuclear Medicine modalities – SPECT, SPECT/CT, PET/CT and PET/MRI with different radiotracers. Every year vendors release new versions of equipment and software, expanding our diagnostic capabilities. On the other hand, overall cancer morbidity grows worldwide due to different factors. That is why we need some updates about patient management in Radiology and Nuclear Medicine and usage of new diagnostic approaches, such as Whole-Body Diffusion Weighted Imaging. Content: The presentation reflects the current capabilities of DWI-MRI in oncology and among non-oncological diseases, the technical principles of obtaining good quality diagnostic images in acceptable scantime, indications for carrying out, and the place of the DWI-MRI method in a wide range of competing modalities of radiology and nuclear medicine. Conclusions: With current technical capabilities, DWI-MRI can be used in oncology for primary N- and M-staging, restaging and monitoring patients with most common types of malignant tumors on a par with FDG-PET/CT at comparable accuracy. With the help of DWI it is possible to evaluate the tumor response to chemotherapy at an earlier time. DWI-MRI can potentially replace traditional skeletal scintigraphy for the evaluation of metastatic bone lesions, as a non-invasive method not associated with ionizing radiation. DWI could be a promising technique in rheumatology in evaluation of multiarticular or extended process.