Twenty-nine intubated pediatric patients were prospectively studied to determine whether nontypable Haemophilus influenzae (NTHI) is associated with the development of nosocomial pneumonia. Throat cultures and tracheal Gram stains, leukocyte counts and cultures were obtained immediately following intubation, then serial studies on tracheal secretions were performed. Median patient age was 13 months. One patient had preexisting lung disease and 14 (48%) had pneumonia when intubated. There were five deaths. NTHI was recovered from the initial throat or tracheal culture in seven patients (24%); none developed a nosocomial lower respiratory tract infection. NTHI was not associated with any of three cases of nosocomial pneumonia. Three of 12 NTHI isolates were beta-lactamase producers. Tracheal leukocyte counts and Gram stains were not predictive of pneumonia, either at the time of intubation or subsequently. We conclude that NTHI in the oropharynx or trachea is not predictive of pneumonia among intubated pediatric patients.