Objective.Increasing rates of antibiotic resistance have stimulated efforts to decrease antibiotic use. To assess the success of these efforts, we analyzed antibiotic prescribing trends in children younger than 5 years old, the group with the highest use, from 1993 to 1999.Methods.Data from the National Ambulatory Medical Care Survey were analyzed to determine antibiotic prescribing patterns for office-based visits from 1993 to 1999 for children <5 years old. Data were stratified by US regions, patient’s race and gender. Antibiotic prescription rates per 1000 population were calculated with population data from the US Census Bureau as the denominator. Specific prescribing of penicillins, cephalosporins, macrolides and sulfas was also assessed.Results.Overall antibiotic prescribing in the office-based setting peaked in 1995 at 1191 antibiotic courses per 1000 children, then declined to 698 per 1000 in 1999, a decrease of 41%. Antibiotic prescribing was consistently higher in whites than blacks; however, declines in prescribing over time were observed in both groups. Although there was wide regional variation in antibiotic prescribing in the early 1990s, by the late 1990s prescribing rates were similar in all regions. Prescriptions for penicillins and cephalosporins combined comprised 77 and 70% of total prescriptions during 1993 to 1997 and 1998 to 1999, respectively. Macrolide prescriptions reached a nadir during 1993 to 1997, accounting for 9% of the total, but increased to 16% during 1998 to 1999.Conclusion.Since 1995 the rates of antibiotic prescriptions in children <5 years of age have declined substantially. At the same time changes have occurred in the types of antibiotics prescribed. It appears that efforts to reduce antibiotic use have been successful. Whether this decrease in use will be accompanied by lower rates of antibiotic resistance will need to be determined.