BACKGROUND: Evaluating the function of facial nerve is essential in order to determine the influences of various treatment methods. The aim of this study was to evaluate and assess the agreement of Photoshop scaling system versus the facial grading system (FGS).METHODS: In this semi-experimental study, thirty subjects with facial nerve paralysis were recruited. The evaluation of all patients before and after the treatment was performed by FGS and Photoshop measurements.RESULTS: The mean values of FGS before and after the treatment were 35±25 and 67±24, respectively (p<0.001). In Photoshop assessment, mean changes of face expressions in the impaired side relative to the normal side in rest position and three main movements of the face were 3.4±0.55 and 4.04±0.49 millimeter before and after the treatment, respectively (p<0.001). Spearman's correlation coefficient between different values in the two methods was 0.66 (p<0.001).CONCLUSIONS: Evaluating the facial nerve palsy using Photoshop was more objective than using FGS. Therefore, it may be recommended to use this method instead.