Introduction: Once-daily tramadol extended-release (ER; ULTRAM^® ER) was evaluated in a randomized, double-blind, placebo-controlled, parallel-group study in 1,020 patients with radiographically-confirmed osteoarthritis (OA) of the knee or hip. Patients were randomized to tramadol ER 100, 200, 300, or 400 mg once daily or matching placebo for 12 weeks. Compared to placebo, all tramadol ER doses achieved significant improvement at Week 12 in WOMAC OA Index composite score, and the subscale scores for pain, physical function, and joint stiffness (P ≤0.05). Significant improvement compared to placebo was seen in pain related sleep parameters on the Chronic Pain Sleep Inventory (CPSI) scores at Week 12 with less trouble falling asleep due to pain, being awakened by pain during the night and in the morning, and in sleep quality (P≤0.05). This analysis evaluated tramadol ER in patients ≥65 years (n=317) from this study. Methods: Patients rated their arthritis pain utilizing a 100-mm (0=no pain, 100=extreme pain) visual analog scale (VAS). Sleep effects were evaluated using the CPSI based on a 100-mm VAS (0=never, 100=always). Results: Compared to placebo at Week 12, this analysis demonstrated: a significant improvement in the pain and joint stiffness subscales of the WOMAC OA index and the composite score for tramadol ER 200 mg and 300 mg, and in the physical function subscale in the 300-mg group; a significant improvement for less awakening by pain in the morning (100-, 200-, 300-mg groups); a significant improvement for less awakening by pain in the night (200- and 300-mg groups); and significantly better sleep quality and less trouble falling asleep (200-mg group; P <0.05 all parameters). The most commonly reported adverse events were constipation, dizziness, nausea, and somnolence. Conclusion: Based on this analysis, tramadol ER should be considered for the management of moderate-to-moderately severe chronic pain associated with OA in elderly patients.