BACKGROUND: normal surface electromyography (sEMG) of muscles involved in swallowing. PURPOSE: to investigate if the literature indicates normal parameters for duration, amplitude and characteristics of the electromyograms of the muscles involved in swallowing (orbicularis oris, masseter, muscles of the suprahyoid muscles and the infra-hyoid region covered by the platysma muscle). CONCLUSION: the search resulted in 33 references, of which only five were within the inclusion criteria. Only one reference was classified with good level of quality by the Jadad scale with modifications. The selected articles cannot point reliable reference values mainly for EMG amplitude and morphology, because they used a inappropriate sampling rate for the EMG recordings that maximizes the achievement of distorted data for the muscle activity. Literature suggests the normalization of techniques for the electromyographic signal due to the variability between and among subjects.