The aim of this double-blind randomised controlled trial was to evaluate the feasibility of a study to compare differences using electromyographic (EMG) or nerve conduction studies (NCS), questionnaires completed by patients, and range of movement, after selective supraomohyoid neck dissection in patients with and without level IIb for node-negative oral cancer. Between January 2006 and July 2008 we recruited 57 previously untreated consecutive patients with node-negative T1 or T2 squamous cell carcinomas (SCC) of the anterior twothirds of the tongue and floor of the mouth. Thirty-eight patients were randomised (32 unilateral and 6 bilateral dissections) into two groups. Preoperatively and at 6 weeks postoperatively we collected EMG or NCS data on trapezius muscle activity (primary outcome), the University of Washington quality of life scale (UWQoLv4), the neck dissection impairment index (NDII), and range of movement. At 6 months data on range of movement and data from the questionnaires were obtained. There was a greater mean fall in trapezius M-response amplitude for those who had IIb dissected, which suggested that inclusion of this level caused additional morbidity. However, it was not significant for patients who had unilateral dissections or for all necks combined. Changes in M-amplitude from baseline to 6 weeks, and from baseline to 6 months were strongly associated with changes in the shoulder domain of the UWQoL and the NDII, but were less strong for change in range of movement. This feasibility study has shown that a randomised controlled trial (RCT) is achievable. The combination of EMG or NCS with questionnaire data preoperatively and to 6 weeks would suffice and would simplify a new study design.