OBJECTIVE: MRI findings of adhesive capsulitis (AC) have been rarely documented even though the disease is a rather common disorder. To find reliable MRI parameters, we studied MRI findings of the patients with arthrographically-proven AC. METHOD: Eighteen patients with AC (patient group) and eight subjects without AC (control group) were enrolled. Mean age of the former was 55.1 years and that of the latter was 41.4 years. Mean duration of the diseases in patient group was 5.9 months. Oblique coronal and axial MRI images of the shoulder were measured for the thickness of capsule and synovium around the axillary fold (TAF), volume of axillary recess (VAR), and volume of biceps tendon sheath (VBTS), which were compared in both groups using unpaired t-test. RESULTS: TAF was significantly increased in patient group (p<0.0001), and the thickened axillary fold greater than 5.1 mm was a useful MRI criterion for the diagnosis of AC with sensitivity of 93% and with specificity of 100%. VBTS was also significantly diminished in patient group (p<0.05), whereas there was no significant difference in VAR between two groups. CONCLUSION: TAF, especially greater than 5.1 mm, and decreased VBTS are useful MRI parameters for the diagnosis of AC of shoulder.