Osseous fatigue injuries occur as a result of cumulative stresses placed upon physiologically normal bone. Such injuries are frequently encountered in athletes and military recruits. Particularly in athletes, the early diagnosis of stress injury is essential to prevent the development of more serious injury, to facilitate rehabilitation and to enable early return to training and competition. Imaging plays a central role in prompt diagnosis as clinical evaluation alone may not be able to differentiate stress injury from other common causes of musculoskeletal trauma. This chapter will review the role of imaging, in particular MR imaging, in providing an accurate diagnosis, guiding treatment and rehabilitation.