Children are often treated with antiinfective drugs, both in and out of hospital, but few studies of antiinfective drug use in paediatric departments have been published. We have analysed the dispensing of antiinfective drugs from hospital pharmacies to all eight paediatric departments in south-eastern Norway (Health region 2) during the years 1990-95. The total consumption of antiinfective drugs, measured by the number of defined daily doses (DDD), did not increase during the study period, though the total costs for such drugs increased by 48% for all eight departments. In 1995 the antiinfective drug use varied between 15 and 30 defined daily doses per 100 bed days. The total use of cephalosporins increased significantly. For vancomycin, antifungal drugs and antiviral agents, both consumption and cost increased in several departments. Knowledge of the total use of antiinfective drugs may be important when evaluating treatment regimens, especially with regard to microbial resistance.