Introduction Chemoradiotherapy treatment for head and neck cancer (HNC) can have a major impact on swallowing function and health-related quality of life. The use of outcome measures in early detection of patients with swallowing problems provides the opportunity for targeting speech and language therapy (SLT) interventions to aid adaption and promote better clinical outcomes. Objective The purpose of the present study was to assess relationships between four outcomes measures over time, in a cohort of HNC patients, treated by (chemo-)radiotherapy. Methods Data were collected at 3 months and 12 months, on 49 consecutive patients with primary squamous cell cancer of the oropharynx, nasopharynx or hypopharynx stage T1-4, N0-2b, M0 disease. Results Out of 49 eligible patients, 45 completed assessment at 3 months and 20 at 12 months. The 3-month outcomes gave a strong indication of performance at 1 year. There were several strong correlations found between measures. The strongest was between the 3-month Performance Status Scale for Head and Neck Cancer (PSSHN) and the 12-month PSSHN (rs = 0.761, n = 17), the 12-month PSSHN and the 12-month Functional Oral Intake Scale (FOIS) (rs = 0.823, n = 20), and the 12-month University of Washington Head and Neck Quality of Life (UWQoL) swallow and the 12-month Water Swallow Test (WST) capacity (rs = 0.759, n = 17). Conclusion The UW-QoL swallow item and WST are easy to incorporate into routine care and should be used as part of a standard assessment of swallow outcome. These measures can serve to help screen patients for dysfunction and focus allocation of resources for those who would benefit from more comprehensive assessment and intervention by SLT.