The sensitivity and specificity of the simple swallowing provocation test (S-SPT) were evaluated in a group of patients who were being examined for aspiration pneumonia (ASP) (ASP group: 72.5 +/- 3.9 years old) and in a group of age-matched control subjects (CTRL group: 69.5 +/- 2.9 years old). The S-SPT was evaluated in terms of the swallowing response and latent time (LT) for swallowing after a bolus injection of 0.4 ml of distilled water at the suprapharynx. Responses to the S-SPT were classified as normal or abnormal, dependent on induction of the swallowing reflex within 3 seconds after bolus injection. The sensitivity and specificity of the S-SPT in detecting ASP were calculated. Of the 40 patients in the ASP group, 18 were given a diagnosis of ASP on the basis of clinical findings and laboratory examinations. The sensitivity and specificity of the S-SPT were 94.4% and 86.4%, respectively, compared to 77.8% and 68.1%, respectively, for the water swallowing test. Because the S-SPT can be performed without any need for special patient effort or cooperation, it should be effective in diagnosing ASP in a wide variety of patients, including those who are bedridden.