Background: This study aimed to compare the efficacy, acceptance and side effects of intramuscular tramadol and ketorolac in combination with oral paracetamol in the emergency setting. Materials and methods: This was a randomised, double blind controlled trial. Patients aged 18 years or above with moderate to severe musculoskeletal pain were recruited. Patients with known allergy, currently on psychiatric medication, with alcohol or opioid dependence, during pregnancy and with major systemic illness were excluded. Tramadol 100 mg or ketorolac 30 mg was given intramuscularly together with paracetamol 500 mg per oral. They were then bed rested in the observation ward for one hour. Visual analogue scale (VAS), satisfaction score, vital signs and side effects were recorded. Results: Altogether, 78 (M: 43, F: 35) subjects were recruited from June to September 2005, with equal number in each arm. The mean age was 39.9 for the tramadol group and 43.9 for the ketorolac group. Most of them suffered from back pain (66.7%). There was a significant difference in VAS improvement between the two groups (0.88; P=0.01). However, there were no significant differences in patients' satisfaction score and admission rate. The incidence of side effects was similar between the two groups (tramadol 19, ketorolac 17), mainly dry mouth, and none were major. The tramadol group had more nausea. Conclusion: The analgesic effect of the tramadol and paracetamol combination is as effective as the ketorolac and paracetamol combination. Tramadol is well tolerated and relatively safe. It is also cheaper than ketorolac. Hence, we recommend tramadol and paracetamol combination for acute moderate to severe musculoskeletal pain in the emergency setting.