With the increasing incidence of thyroid cancer, cancer was discovered at an earlier stage. This is due to new clinical features of thyroid cancer, such as the decrease in tumor diameter, the lower rate of extrathyroid extension and of cervical lymph node metastasis. Routine ultrasound survey during physical examination has become the most common way to detect thyroid cancer. Increasing usage of diagnostic scrutiny, including the ultrasound survey, has most likely contributed to the increased incidence through detection of small thyroid cancers. Increased use of ultrasound to screen thyroid cancer in early stages should lead to better therapeutic outcome.