Background Infective endocarditis during pregnancy is a rare condition that compromises the health of both the mother and the foetus, presenting high rates of morbidity and mortality. The clinical manifestations of this disease are varied, with embolic phenomena being a frequent presentation.Case summary We report the case of a Hispanic 37-year-old patient, at 29 weeks of pregnancy, with no known cardiovascular history, who presented with 48 h of sudden mandibular and lingual pain. The study showed acute thrombosis of the right lingual artery and the rest of the right external carotid artery. In this context, searching for the origin of the embolism, acute mitral valve endocarditis was diagnosed, which was effectively treated with antibiotic therapy and biological mitral valve replacement, as well as early delivery.Discussion We report the first case where lingual artery thrombosis was the key diagnostic feature of infective endocarditis.