Background: For the N1b papillary thyroid carcinoma (PTC) patients, modified radical neck dissection (MRND) encompassing levels II – V is generally recommended. However, routine level V dissection is controversial because of the low incidence of metastasis/recurrence in level V and the increased morbidities associated with level V dissection. Objective: This study was designed to determine the clinical risks and benefits of routine level V dissection in N1b PTC patients with clinical negative level V. Patients and Methods: This study was a prospective, comparative, randomized and descriptive study of 40 patients suffering N1b papillary thyroid carcinoma. The patients were divided into two equal groups: Group 1 subjected to MRND, and Group 2 subjected to SND. Both groups were compared for age, sex, intraoperative (duration of surgery and complications) and postoperative results (complications and distribution of lateral nodal recurrence). Results: Under a matched condition, occult level V metastasis was observed in 5.0%. The MRND group exhibited a significantly longer operation time compared with the SND group. The amount of drainage was significantly more in the MRND group compared with the SND group. Time of drain removal was significantly less in the SND group compared to MRND group. Chyle leak was more frequent in the MRND group compared with the SND group but not statically significant. Level V recurrences did not occur in 3 recurred N1b PTC patients who underwent unilateral MRND and SND. Shoulder syndrome encompassing shoulder dysfunction and pain was significantly more frequent in the MRND group than in the SND group. There were no statistically difference between the groups according to infection, transient hypocalcaemia, transient RLN palsy and nodal recurrence. Conclusion: Because of the low incidence of metastasis/recurrence in level V and the clear evidence of increased morbidities, level V dissection in N1b PTC patients may be reserved for those clinically/radiologically evident metastasis in level V.