Myositis ossificans traumatica (MOT) of the temporal muscle is an extremely rare disease. A limitation of mouth opening is a key symptom. Imaging is very useful for diagnosis. The computed tomography scanner of the face is the most efficient for the detection of the MOT. Complete surgical resection is the best treatment. Cases of MOT in the head and neck area are rare. Cases of isolated temporal muscle involvement are even rarer. We present the case of an isolated ossification of the left temporal muscle after polytrauma. The interest of the clinical observation of the case presented is thus to document the literature. The differential diagnosis and pathognomonic signs present on the imaging examinations will also be detailed.