Although modern high-resolution real time ultrasound equipment permits excellent visualisation of the thyroid nodules, their ultrasonic appearance and characteristics do not accurately predict the histological result. Ultrasound allows the whole thyroid and adjacent lymph nodes to be examined. It is regarded as valuable in differentiating between solid and cystic lesions and single or multiple lesions. But predictive positive values of ultrasound in suggesting malignant diagnosis is not so doubtful as it can be said. An hypoechoic lesion is more often malignant and it can be one criterion among many which can help clinician to select patients who must undergo surgery. Ultrasound guided fine needle biopsy is useful in these cases.