Background: Head and neck cancer (HNC) patients are often challenged by treatment induced dysphagia and trismus. Traditionally, rehabilitation is initiated when loss of function has already occurred. There is increasing evidence that it is of benefit to patients to initiate an early rehabilitation process before and during treatment. HNC patients have a unique set of functional challenges such as pre- and post-treatment dysphagia, pain and weight loss. The aim of the trial is to investigate the effects of swallowing and mouth-opening exercises combined with progressive resistance training (PRT) during radiotherapy. This report presents the protocol, interim inclusion and feasibility data. Material and methods: The trial (clinicaltrials.gov NCT02385929) is a multicenter randomized controlled trial (RCT) with a parallel-group randomization (1:1). The planned sample size of 240 HNC patients is randomly assigned to either (1) twice weekly PRT and three times weekly swallowing exercises by physio- and occupational therapists, respectively, as well as daily home exercises throughout radiotherapy or (2) standard care. Inclusion criteria are patients with cancer in the larynx, pharynx, oral cavity, or unknown primary tumor who are referred to radiotherapy with curative intent. Outcomes are measured at end-of-treatment and two, five, and 12 months post-treatment. Interim results: In 16 months, 321 HNC patients were screened for eligibility. Of these, 131 (41%) were eligible according to inclusion criteria. One-hundred-and-fifteen patients were invited to participate of which 69 (60%) were enrolled in the trial and randomized for either intervention or control group with 10 drop-outs (14%). The six pilot patients adhered more than 90% to the program. Conclusion: Preliminary results show that exercise according to protocol is tolerable and feasible.