Abstract The aim of this study was to evaluate the effects of orofacial physiotherapeutic treatment (OPT) on the facial mobility of Parkinson's disease (PD) sufferers. Sixteen participants with PD were allocated randomly to either the Treatment group or the Control group. A short interview between the physiotherapist and each subject was videotaped, and 10 random frames of the videotape were selected to be used in the facial expression assessment. The quantification of facial expressions was achieved by using an objective microcomputer-based measurement system, based on a mathematical model of the face (FACEM). A facial outline is obtained, as well as 12 facial measures, which represent distances between key facial landmarks. The facial assessment was performed on 3 separate occasions, that is, baseline (pretreatment), posttreatment, and follow-up (4 weeks later). A repeated measures analysis of variance (MANOVA) revealed a significant main effect of Time and a significant interaction effect between Time and Group for the Mouth-Opening Measure, suggesting that after treatment, members of the Treatment group opened their mouths to a greater degree than members of the Control group. Within the Treatment group, significant differences between pretreatment and posttreatment scores (MANOVA) were found for Mouth-Opening Measure and Mid-Top-Lip Measure. Similarly, Mouth-Opening Measure, Mid-Top-Lip Measure, Lower-Lip Thickness Measure, Top Eyelid/Iris Intersect Measure and Lower Eyelid/Iris Intersect Measure were significant across time from baseline to follow-up in the Treatment group only. No significant differences were found on any of the facial measures during the same period for members of the Control group. These findings suggest that OPT can improve facial movement and that this benefit extends in time, beyond the period of OPT itself. Such an increase in facial mobility can be expected to modify the “Parkinsonian facies” and facilitate the display of facial expressions.