Thyroid carcinoma ranks low in incidence and as a cause of death when compared to carcinomas arising in the other site. With adequate surgical treatment, the prognosis of operable thyroid carcinoma is good. However, the extent of surgical resection in treatment of thyroid cancer remains still controversy. The aim of this study was to assess the results of thyroid cancer patients treated surgically and to analyze the prognostic factors affecting survival and to improve the survival rate. We retrospectively analyzed the outcome of a total of 278 thyroid cancer patients treated surgically at Inje University Paik Hospital from 1980 to 1995 and followed for 1 to 16 years. There were man in 47 and woman in 231 patients with age range of 14 to 79 years(mean 42 years). Histopathologic findings were papillary carcinoma in 233, follicular carcinoma in 33, mixed carcinoma in 7, medullary carcinoma in 2, and undifferentiated carcinoma in 3 patients, respectively. Operative procedures were unilateral lobectomy in 111, subtotal thyroidectomy in 100, and total thyroidectomy in 67 patients. Central node dissection was performed in 92, modified neck disseciton in 62, radical neck dissection in 28, and no node dissection in 96 patients. Thyroid hormone was administered for the period of 3 to 5 years to suppress endogenous TSH production. Overall 5-year survival rate according to Kaplan-Meier method was 91.1%. Independently, significant factors affecting the prognosis were age at diagnosis, tumor size, pathologic type, tumor stage, lymph node metastasis, angioinvasion, extrathyroidal extension, and 'risk' group category. but, the prognosis were not influenced by sex and capsular invasion. Patients at low risk or with small size carcinomas had long survival over 5 years with only lobectomy. Lymph node dissection was carried out with a limited type in no jugular metastasis, radical neck dissection was performed only therapeutically in proved jugular node metastasis. Fifteen patients were dead of tumor recurrence after surviving for three months to two and half years, and the cause of death was local recurrence in nine, bone metastasis in four and lung metastasis in two patients. In conclusion, more extensive surgery including total thyroidecotmy and systematic compartment-oriented dissection of the lymph node metastases in patient at high-risk group will results in better survival and lower recurrence rate.