1. Objectives The purpose of this case study is to report the effects of Sukjiwhanggosam-tang which is based on the Sasang Constitutional Medicine for the Foot drop caused by peroneal nerve palsy. 2. Methods This patient was treated by Sukjiwhanggosam-tang according to the result of Sasang Constitutional diagnosis. We used Visual analogue scale(VAS), Range of motion(ROM) and Manual Muscle Testing(MMT) to evaluate the improvement of the Foot drop. 3. Results After 20 days treatment, the VAS of Rt. leg & foot hypoesthesia decreased from 10 to 2. The ROM of dorsiflexion of the ankle joint increased from $10^{circ}$ to $30^{circ}$ and the grade of MMT increased from 3 to 4. 4. Conclusions This case study shows an efficient result of using Sukjiwhanggosam-tang in the treatment of the Foot drop caused by peroneal nerve palsy.