The facial palsy produced by a parotid tumour, could be misdiagnosed due to the absence of a palpable mass or other any signs in the computerized axial tomography or nuclear magnetic resonance. However there are data derived from the facial anatomy, course and clinical characteristics from the palsy that could make us thinking on the presence of a parotid tumour. The objective of this article is to present this characteristics, together with a serial of clinic cases which coursed in the beginning with a facial palsy and had problems in their diagnostic. It's also remarked the significance of the presence or not of perineural infiltration to the parotid tumours that will condition not only the prognosis but also the clinic course.