To investigate the pattern of antibiotic use in the pulmonology wards of four children's hospitals in China from 2002 to 2006. The Anatomical Therapeutic Chemical Classification/Defined Daily Doses (ATC/DDD) methodology was used. Aggregate data on antibiotic use (ATC code-J01) were expressed in numbers of DDD/100 bed-days for inpatients. The overall consumption of antibiotic drugs in the pulmonology wards of the four children's hospitals were 83.7, 49.9, 53.6 and 79.3 DDD/100 bed-days, respectively. Injectables were among the most widely used antibiotics. In addition, there was a considerable variation in both the amount and the pattern of antibiotics used in the respective hospitals' pulmonology wards. Wide variations were found between the four hospitals studied in the amount and type of antibiotics prescribed although the diseases treated appeared the same. This variation may have been due to differences in disease severity, regional diversity in bacterial resistance or variations in empiric treatment regimens. Despite the introduction of Chinese Ministry of Health Antibiotic Guidelines in 2004, the pattern of antibiotic use in individual hospitals remained unchanged from 2002 to 2006. Antibiotic utilization studies need be taken to the next level; comparing drugs used to treat specific diseases with guideline recommendations. In addition, educational and other interventions to ensure better compliance with guidelines are urgently required.