Abstract: Objective: To investigate the relationship between severity grade for radiography, magnetic resonance (MR) imaging, and computed tomography (CT); clinical severity; and recovery time from a tibial stress injury (TSI), as well as to evaluate inter-assessor grading reliability. Methods: A total of 34 cases of military soldier with TSI were included and mean age of all the participants were 19.1 yrs. All the TSI patients were evaluated by X-ray, MR imaging and CT by an orthopedist and a radiologist for the imaging severity. The clinical severity of these patients were assessed with an orthopedist. Statistical analyses were employed to explore the relationship between severity grade for radiography, magnetic resonance (MR) imaging, and computed tomography (CT); clinical severity; and recovery time from a tibial stress injury (TSI), as well as to evaluate inter-assessor grading reliability. Results: Negative associations could be found between X-ray (r=-0.529, P=0.029), MR imaging (r=-0.641, P=0.006), CT (r=-0.573, P=0.016) and clinical severity. No correlation was found between by X-ray, CT and recovery time. A correlation trend was found between MRI and recovery time (P=0.09). The best reliability was MRI (α=0.849), second was CT (α=0.779) and third was X ray (α=0.623). Conclusions: The clinical severity of TSI was negative associated with X-ray, MR imaging and CT grade score. No correlation was found between recovery time and with X-ray, MR imaging and CT grade score.