A procedure is described for quantifying the amount of bolus material retained in the pharynx after completion of a swallow, using radionuclide swallow techniques. Data are derived from scintigraphic time-activity curves. The procedure takes into consideration the differential attenuation of radioactivity through various regions in the body, and expresses the result as a percentage of the total radioactivity in the ingested bolus. Illustrative examples are provided for swallows by normal individuals and patients with head and neck cancer.