Sixteen patients with adhesive capsulitis of the shoulder were treated in an open trial of capsular distension with intraarticular injection of 30mL of fluid containing 8mL of 1% lidocaine, 2mL of corticosteroid, and 20mL of radiocontrast material. A capsular tear during arthrography occurred in all cases. Rupture usually occurred at the subscapular bursa or the subacromial bursa. Rupture at the distal bicipital sheath occurred in two patients and was not associated with pain relief. Thirteen patients experienced immediate pain relief and increased shoulder mobility. This improvement was maintained over a follow-up interval of 6 months. Disruption of the constricted capsule by hydraulic distension seems to be the mechanism for achieving symptomatic relief in adhesive capsulitis.