Patients who have thyroid disease present a treatment challenge to dentists. Awareness of the condition and current stage of treatment is important in understanding the possible modifications needed for dental treatment. Length and current state of therapy are important in understanding the metabolic control of patients. The main complications of patients with hyperthyroidism and hypothyroidism are associated with cardiac comorbidity. Consultation with the patient's primary care physician or an endocrinologist is warranted if any sign or symptom of thyroid disease is noted on examination.