Introduction: In differentiated thyroid carcinoma (DTC) lymphnodes are the most common metastatic site. Aim of study was to evaluate ifcervical lymph node (CLN) metastases significantly affect prognosis in DTC patients.Patients and Methods: The population of the study was composedof two groups. The first group consists of 82 patient of DTC and CLNmetastasis ; while the second group, the control group, consists of 82patients of DTC but without CLN metastasis. Results: Comparingthe two groups for morbid-mortality revealed the following : No statistically significant differences regarding morbido-mortality inrespect to age, gender, papillary pathology, tumor-size 1 cm andtumor uni-focality.Statistically significant differences regarding morbido-mortality inrespect to follicular pathology, tumor-size ≥1 cm, tumor multifocality,positivity of follow-up tools [Dx-WBS, TG and cervicalsonography].The complete ablation success rate after the first dose of RAI131 was63.4% and 81.7% in the LN and control groups respectively [P 0.03].A second ablation dose of RAI131 was needed in 36.6% vs. 18.3% inthe LN and control groups respectively [P 0.04].In the LN group a third and fourth of RAI131 was given vs. none ofthe control group [P 0.001].