Study objective: We determine whether pain treatment with acetaminophen was not inferior to nonsteroidal anti-inflammatory drugs or the combination of both in minor musculoskeletal trauma. Methods: The Paracetamol or NSAIDs in Acute Musculoskeletal Trauma Study was a double-blind, randomized, clinical trial conducted in 2 general practices and 2 emergency departments in the Netherlands. A total of 547 adults, aged 18 years and older, with acute blunt minor musculoskeletal extremity trauma were randomly assigned in a 1:1:1 ratio to acetaminophen 4,000 mg/day, diclofenac 150 mg/day, or acetaminophen 4,000 mg/day+diclofenac 150 mg/day during 3 consecutive days. Patients, health care staff, and outcome assessors were blinded for treatment allocation. Follow-up for each patient was 30 days. Primary outcome measures were between-group differences in mean numeric rating scale (NRS) pain scores in rest and with movement at 90 minutes after initial drug administration compared with baseline pain scores with a predefined noninferiority margin of 0.75 NRS points. Secondary outcomes included NRS pain scores during 3 consecutive days and need for additional analgesia. Results: One hundred eighty-two patients were treated with acetaminophen, 183 with diclofenac, and 182 with combination treatment. Intention-to-treat analysis revealed mean NRS reduction in rest -1.23 (95% confidence interval [CI] -1.50 to -0.95) and -1.72 (95% CI -2.01 to -1.44) with movement, both for acetaminophen at 90 minutes compared with baseline. Pairwise comparison in rest with diclofenac showed a difference of -0.027 (97.5% CI -0.45 to 0.39) and -0.052 (97.5% CI -0.46 to 0.36) for combination treatment. With movement, these numbers were -0.20 (97.5% CI -0.64 to 0.23) and -0.39 (97.5% CI -0.80 to 0.018), respectively. All differences were well below the predefined noninferiority margin. Conclusion: Pain treatment with acetaminophen was not inferior to that with diclofenac or the combination of acetaminophen and diclofenac in acute minor musculoskeletal extremity trauma, both in rest and with movement.