We have investigated the feasibility of using the intense synchrotron X-radiation to microradiographically image both surface and internal cracks in reasonably thick (200 μm) specimens of aluminum base alloys. It is concluded that synchrotron micro-radiography can be successfully used to image such defects as fatigue microcracks, creep induced wedge cracks and notches with a reasonable contrast and within exposure times of about a minute or less. The resolution capability of this technique is about 20 μm which is better than the currently available NDE techniques such as ultrasonics and macroradiography. Means for improving contrast and resolution without sacrificing the short exposure time capability are suggested. © 1980 American society for metals and The metallurgical society of AIME.