ABSTRACT Purpose characterize the swallowing muscles electromyographic activity in EM. Methods we evaluated 60 individuals being 30 with definitive diagnosis in EMG and 30 without neurologic changes. Volunteers provided personal data through interview, and we also obtained data from clinical records on the time of diagnosis, disease clinic form and the EDSS scale score. We then administered the DYMUS questionnaire. All evaluations occurred according to the Swallowing Electromyographic Evaluation Protocol. Results Saliva swallowing, liquid swallowing with comfortable volume and continuous swallowing showed differences in the groups at the masseter, with higher averages in the comparison group. We verified differences between masseter and supra hyoid in each group, at rest, in saliva swallowing, liquid swallowing with comfortable volume and continued swallowing. In all situations the averages were higher in the supra hyoid, being that the smaller difference occurred at rest and the higher at continuous swallow. We recorded correlations between EDSS and the activity of supra hyoid at saliva swallow, liquid swallow with comfortable volume and swallow continuous. With the DYMUS, we observed correlations with the masseter activity and with the swallowing time. The high punctuation at the DYMUS presented correlations with the increase electrical activity of the masseter. Conclusion patients with more severe conditions show lower supra hyoid electric activity, and the electric activity of the masseter is related to difficulty in swallowing.