BACKGROUND: Low back pain (LBP) occurs as a common condition and may harm the patient's quality-of-life. Non-steroid anti-inflammatory drugs (NSAIDs) and eperisone form a drug regiment that has been reported as effective in improving low back pain, yet the evidence for its efficacy and safety is lacking. OBJECTIVE: The aim of this study was to evaluate the effect of eperisone hydrochloride and ibuprofen compared with ibuprofen alone in reducing symptoms of patients with acute non-specific back pain with a muscle spasm. METHODS: This was an open-label, prospective study involving 100 subjects with symptoms of back pain and muscle spasm. Eligible participants were randomly allocated to an experimental group (54 patients) and a control group (46 patients). The experimental group received eperisone 50 mg three times daily + ibuprofen 400 mg twice daily, and the control group received ibuprofen 400 mg twice daily over a 4-week duration. The primary outcomes were measured with the visual analog scale (VAS), and finger-to-floor (FTF) distance at baseline, week 2, and week 4. RESULTS: After 4 weeks of follow-up, results from 59 subjects were collected. In both groups, VAS and FTF were decreased compared to baseline. Clinically significant pain reduction (>50% than baseline) was observed to be higher in the experimental group compared with the control group in the fourth week (72.4% vs 46.7%, <0.05). At the end of the study, pain reduction in the experimental group was more significant compared to the control group (28.13±24.72 vs 34.42±28.47) and participants mobility (FTF distance <10 cm) improved in both groups, especially in the experimental group (75.9% vs 70%). There was no difference in adverse events between groups (>0.05). CONCLUSION: The combination of eperisone hydrochloride and ibuprofen effectively reduces pain and improves functional outcomes over ibuprofen alone with a similar safety profile in these patients with acute non-specific back pain with muscle spasm.