Seventy-four transtracheal aspirations and expectorated sputum specimens were collected from a number of children with aspiration pneumonia. The aspirates were cultured for aerobic and anaerobic bacteria. Cultures obtained through TTA contained fewer pathogens than in cultures of expectorated sputum. Gram stains of TTA aspirates offered prompt presumptive bacteriologic diagnosis in 93% of patients, whereas Gram stains of expectorated sputum were not specific. The recovery of Gram-negative enteric rods in the TTA aspirate provided guidance in adding an aminoglycoside to the antimicrobial therapy in 35 children (47%). Side effects of TTA included mild hemoptysis and, in rare instances, subcutaneous emphysema. We found TTA to be a generally safe and useful procedure in the diagnosis and therapy of aspiration pneumonia in children.