Otalgia with mastoiditis is an infrequently encountered complication of acute otitis media (Pfaff and Moore, 2018). Even more rare is the development of infected jugular venous thrombosis, Lemierre's disease. We present a case of a six year-old girl with otalgia for over two months who presented to our Emergency Department (ED) with clinical mastoiditis, confirmed on CT scan, as well as an incidental diagnosis of complete thrombosis of the internal jugular (IJ) vein, Lemierre's syndrome. The true prevalence of Lemierre's from mastoiditis is difficult to discern. This clinical case highlights the importance of the consideration of these pathologies by the emergency physician.