Patients treated surgically for cancer of the tongue are expected to have difficulty in eating, drinking and swallowing. The authors of this paper report on a cohort of 106 patients in their practice who had surgical resection as primary treatment. They noted the following key variables: tumour stage, location, volume, surgical approach used (with/without reconstruction) and whether adjuvant radiotherapy was indicated. They propose a defect classification system and compare this with swallowing outcomes obtained using the Functional Oral Intake Score (FOIS) and specific videofluoroscopy parameters (VFS) including oral and pharyngeal transit times and penetration-aspiration (PAS) score. Location of the tongue defects were classified as: lateral tongue, sulcus tongue, tongue tip, tongue base. Volume was classified as the amount of resection judged by the surgeon using a consistent method at the time of surgery: Class I (less than a third); Class II (one third to half); Class III (half to two thirds); Class IV (total tongue). The mean time of swallowing evaluation was 14 months post-surgery: more than 85% of patients obtained a FOIS score of four and above (independent of a feeding tube). Location of defect did not have significant implications for Class I and II. In Class III, sulcus defects affected oral stage, and tongue-base defects affected pharyngeal stage most notably. The significant predictors for poorer outcome when tested against VFS parameters were advanced T stage, surgical approach (e.g. mandibulotomy), volume of glossectomy defect and radiotherapy. On multivariate analysis volume of defect was an independent predictor for oral residue and oral phase problems, and radiotherapy was an independent predictor for pharyngeal difficulties including penetration-aspiration, pharyngeal transit time and pharyngeal phase problems. This paper offers a useful classification system that may guide reconstruction choices and also assist in providing more nuanced information when counselling a patient and planning rehabilitation targets.