Background Bells palsy involves acute facial paralysis due to inflammation of the facial nerve. Acupuncture and moxibustion (acu-moxi) is beneficial in treating facial palsy. In order to verify the efficacy of acu-moxi on Bells palsy, a randomized single-blind, multicenter clinical trial was performed.Methods A total of 480 patients from four clinical centers were involved in this trial, of whom 439 completed the trial and 41 did not. All patients were randomly assigned to either the control group or to one of two treatment groups. The control group was treated with prednisone, vitamin B1, vitamin B12, and dibazole; the treatment groups were treated either with acu-moxi alone or in combination with prednisone, Vitamin B1, vitamin B12, and dibazole. Symptoms and signs, the House-Brackmann scale, and facial disability index (FDI) scores were assessed and determined both pre- and post-treatment to evaluate the effectiveness of the treatment methods.Results The characteristics of the control and two treatment groups were comparable without statistically significant differences before treatment. There were significant differences between the control and treatment groups after treatment (χ2=15.265, P=0.018). According to evaluations based on the House-Brackmann scale and FDI scores, the effectiveness of treatment in the two treatment groups was better than in the control group and was most effective in patients receiving acu-moxi treatment alone (Z=-2.827, P=0.005). Conclusion The efficacy of acu-moxi treatment for Bells palsy is verified scientifically.