BACKGROUND: Adhesive capsulitis, also termed "frozen shoulder," is controversial by definition and diagnostic criteria that are not sufficiently understood. The clinical course of this condition is considered self-limiting and is divided into three clinical phases. Several treatment methods for adhesive capsulitis have been reported in the literature, none of which has proven superior to others. OBJECTIVES: To evaluate the long-term follow-up of patients with idiopathic adhesive capsulitis who were treated conservatively. METHODS: We conducted a long-term follow-up (range 5.5-16 years, mean 9.2 years) of 54 patients suffering from idiopathic adhesive capsulitis. All patients were treated with physical therapy and non-steroidal anti-inflammatory drugs. RESULTS: An increased statistically significant improvement (P < 0.00001) was found between the first and last visits to the clinic in all measured movement directions: elevation and external and internal rotation. CONCLUSIONS: Conservative treatment (physical therapy and NSAIDs) is a good long-term treatment regimen for idiopathic adhesive capsulitis.