Background: This report describes four cases of cracked tooth syndrome secondary to traumatic occlusion that mimicked trigeminal autonomic cephalalgias. All patients were referred by general practitioners to the Orofacial Pain Clinic at Nihon University Dental School for assessment of atypical facial pain. Clinical Presentation: Case 1: A 51-year-old woman presented with severe pain in the maxillary and mandibular left molars. Case 2: A 47-year-old woman presented with sharp, shooting pain in the maxillary left molars, which radiated to the temple and periorbital region. Case 3: A 49-year-old man presented with sharp, shooting, and stabbing pain in the maxillary left molars. Case 4: A 38-year-old man presented with intense facial pain in the left supraorbital and infraorbital areas, which radiated to the temporoparietal and maxillary regions. All cases mimicked trigeminal autonomic cephalalgias, a group of primary headache disorders characterized by unilateral facial pain and ipsilateral cranial autonomic symptoms. Trigeminal autonomic cephalalgias include cluster headache, paroxysmal hemicrania, hemicrania continua, and short-lasting unilateral neuralgiform headache attacks with conjunctival injection and tearing/short-lasting neuralgiform headache attacks with cranial autonomic features. Pulpal necrosis, when caused by cracked tooth syndrome, can manifest with pain frequencies and durations that are unusual for pulpitis, as was seen in these cases. Conclusion: Although challenging, differentiation of cracked tooth syndrome from trigeminal autonomic cephalalgias is a necessary skill for dentists. Keywords: cracked tooth syndrome, orofacial pain, trigeminal autonomic cephalalgias