Background: whole body diffusion weighted imaging (WB-DWI) has become a standard imaging sequence for the evaluation of patients with cancer. Major advantages of DW MRI imaging include the fact that no ionizing radiation is administered and no injection of isotopes or any contrast medium is necessary, Aim and Objective: The aim of the work is to assess the role of WB-DWI in detection of the metastatic diseases in patients with various histopathologic types of malignancies, patient &Methods: study was carried out in Radiology department of Benha university hospital, where 30 patients were selected , Included patients underwent WB DWI within 1 week of conventional imaging. , Results: There is moderate to good degree of agreement between WB DWI and conventional imaging in the screening of metastasis. However, the use of both evidently increased the accuracy of metastasis detection and increased the possibility of further lesions detections, Conclusion: adding WB-DWI to the routine sequence of metastasis screening increased the possibility of further lesions detections that may be beyond the scope of the requested conventional imaging study.