Purpose: Dysphagia after head and neck cancer treatment is a health care issue; in some cases, the cause of death is not cancer but, rather, the passage of food or liquid into the lungs. Hyoid displacement is known to be important to safe swallowing function. The purpose of this study was to evaluate hyoid displacement after cancer treatment. Method: Hyoid displacement was measured in healthy persons with normal swallowing function, head and neck cancer patients postradiation only, and head and neck cancer patients postsurgery only. Three bolus conditions (5 ml and 10 ml liquid and 5 ml paste) were examined. The influence of 2 different measurement algorithms on the extent of hyoid movement was also explored. Results: Radiation-therapy patients in this study had greater hyoid displacement than did surgery patients. Bolus viscosity and measurement method significantly influenced displacement results, whereas bolus volume did not. However, more multiple swallows occurred with 10 ml liquid; this may account for the apparent insignificance of bolus volume. Conclusions: These findings can be used to assist head and neck cancer treatment planning and counseling. Because hyoid measurement methods influence research conclusions, this aspect of design should be considered when interpreting research findings.