Squamous cell carcinoma of unknown primary (CUP) in the head and neck is difficult to diagnose and treat. This report outlines 11 cases of CUP treated with transoral robotic surgery (TORS), aimed at investigating the diagnostic efficiency of primary tumour and radical resection effectiveness of TORS. 11 cases of CUP among 68 oropharyngeal cancer patients treated by TORS were analysed retrospectively. All the 11 cases received TORS with cervical lymph node dissection. Primary tumours were found in 8 cases (72.7%), 4 cases in the palatine tonsil and 4 cases in the base of the tongue. The average diameter of the primary tumour was 1.65cm. All patients resumed eating by mouth within 24h, no tracheotomy, no pharyngeal fistula and no postoperative death. The 3-year disease-free survival rate was 91%. TORS can improve the diagnostic efficiency of primary tumour of CUP and achieve good oncology and functional results.