The main complication of enteral feeding in prolonged mechanical ventilation via tracheostomy is the subsequent aspiration pneumonia. We used a scintigraphic method for the detection of enteral feeding aspiration and compared the results with clinical evidence of aspiration. The study population consisted of 62 consecutive tracheotomised patients (16 females, age: 64.1 +/- 11.1 years). The swallowing test was done in an upright or semirecumbent body position with the patients spontaneously breathing. The standard feed consisted of a liquid, semiliquid and solid meal which was labelled by 100 MBQ 99 TC. Scintigraphic aspiration (SA) was defined as positive if radioactivity was detected in the bronchial system. Clinical aspiration (CA) was defined as positive if there was cough, choking and distress after swallowing; furthermore, when receiving enteral feeding during suctioning or bronchoscopy. Both clinically significant aspiration (CA) and scintigraphic aspiration (SA) were found to be identical in 10 of 62 (16%) patients. CA, but not SA: 4/62 (6.5%). SA, but not CA (Subclinical aspiration): 4/62 (6.5%). Nor CA neither SA: 44/62 (71%) patients. Radiolabelled feed can be used as a feasible marker to detect aspiration. The test is a useful screening test and strategy to minimize aspiration. The scintigraphic method failed to identify all tracheotomised patients with clinically significant aspiration. However, scintiscanning did suggest that some patients had subclinical aspiration.