Background and Objective: BELL'S PALSY is the most common type of seventh nerve PALSY. Acyclovir has been recommended for treatment of the patients, since some evidences show that herpes virus has a role in this disease. Thus, this study was performed to determine the effect of acyclovir on BELL'S PALSY and to compare it with typical treatment i.e, prednisolone. We also investigated whether combination therapy with these two agents can cause faster improvement and alleviate the complications of the disease.Materials and Methods: This study was a clinical trial and three groups of 26 patients suffering from BELL'S PALSY were included. The patients were randomely assigned to receive prednisolone, acyclovir, prednisolone – acyclovir and the data were analyzed by Kruskal- Wallis test, at the end point.Results: This study showed that improvement ratio in patients who received prednisolone, acyclovir, and prednisolone - acyclovir was 69.23%, 65.38% and 80.76%, respectively. Statistical analysis showed that in the patients received combined prednisolone - acyclovir, the course of treatment was shorter and the response to treatment was faster than the other groups.Conclusion: This study showed that combined prednisolone - acyclovir therapy is more effective and can cause a faster improvement in BELL'S PALSY patients. Also in certain disease such as diabetes which prescription of prednisolone has limitations it is possible to use acyclovir as a substitution.