Intraarticular corticosteroids provide valuable local therapy for chronic joint pain caused by inflammatory joint diseases. In this inpatient study, we evaluated the effect of intraarticular triamcinolone acetonide on acute pain after arthroscopic knee surgery. Sixty patients who underwent arthroscopic knee surgery under spinal anesthesia were enrolled into this double-blind, randomized trial. At the end of surgery, Group 1 (n = 30) received intraarticular triamcinolone acetonide 10 mg in isotonic saline 20 mL, and Group 2 (n = 30) received intraarticular isotonic saline 20 mL. After surgery, pain was assessed by using a visual analog scale. The time to first analgesic request (IV morphine) was recorded, and the proportion of patients requiring rescue analgesia was calculated. The results demonstrated that patients in Group 1 had lower pain scores than those in Group 2 from 6 to 24 h postoperatively (P < 0.05 to P < 0.01). From 6 h to 24 h, no patient in Group 1, compared with 53% of patients in Group 2, requested rescue analgesia (P < 0.001). We conclude that intraarticular triamcinolone acetonide provides a valuable local therapy of acute joint pain after arthroscopic knee surgery. CONCLUSIONS The value of intraarticular triamcinolone acetonide in the management of pain after arthroscopic knee surgery has been evaluated. Patients who received intraarticular triamcinolone acetonide 10 mg at the end of surgery had lower pain scores and used less systemic analgesia than the saline control group. These data are important to the clinical use of this new therapy.