We report a case of familial congenital paresis of ramus marginalis nervus facialis in 5 generations. The paresis varied in location, i.e., 2 right-sided and 3 left-sided, 1 side unknown. The primary patient, a 33-year-old female, presented with a complete right-sided congenital lower lip palsy. Electromyographic examination showed absent voluntary activity of the right depressor labii inferior muscle. There was no evidence of denervation of the paretic muscle. These findings may suggest either absence of the depressor labii inferior muscle or possibly absent voluntary activation due to a defect at brainstem level.