Metastasis of thyroid cancer to the lateral retropharyngeal nodes is unusual. We present two cases of the metastatic spread of cancer of the thyroid to those nodes due to alteration of lymphatic flow resulting from multiple surgical derangement of its normal flow directions.Case 1. A 66-year-old male patient had undergone surgical treatment for recurrent cancer of the thyroid five times during a 20-year interval. Bilateral cervical nodes were palpable and moreover, posterolateral wall of the mesopharynx was found to be swollen. A CT scan of the region disclosed tumorous masses to the retropharyngeal space. At surgery mteastatic extenstion of cancer of the thyroid to those lymph nodes was confirmed.Cases 2. A 59-year-old female patient with twice operations for recurrent thyroid cancer in past 20 years complained of nasal obstruction and snoring. A lprge tumor was revealed at the posterolateral wall of the epipharynx extending to the mesopharynx. A CT scan highly suggested tumorous involvement of the prevertebral fascia and completionn thyroidectomy was carried out in association with I131 therapy.