Objectives To demonstrate the effectiveness of an intervention in antibiotics prescribing, and evaluate the use of antibiotics in the pediatric intensive care unit (PICU) at the Beijing Children's Hospital. Methods Our interventions included (1) educating the pediatricians on antibiotics prescribing, (2) applying an antimicrobial spectrum chart, and (3) controlling the prescription of specific antibiotics with the use of a guideline. Nine hundred clinical records, including clinical information and antibiotic usage data, were selected retrospectatively from the PICU admissions during the pre- and post-intervention periods. Results In this 5-year survey, the mean rate of antibiotic prescribing was greater than 95% in the PICU. More than 76% of the prescriptions were started empirically. The most frequently used antibiotics were third-generation cephalosporins. After the intervention, we found a reduction in the rate of antibiotic cost/patient/day (P < 0.05); a decrease in the prescription rate of third-generation cephalosporins and macrolides (P < 0.01); an increase in the prescription rate of beta-lactam/beta-lactamase inhibitors and second-generation cephalosporins (P < 0.01); a reduction in the empiric treatment (P < 0.01); and a significant reduction in the incidence rates of bacterial resistance for imipenem-, cefepime-, and ceftazidime-resistant Pseudomonas aeruginosa (P < 0.05), and cefepime-resistant Escherichia coli and Klebsiella pneumoniae (P < 0.01). Conclusion Our interventions led to a significant reduction of broad-spectrum antibiotic prescribing associated with the significant reduction in bacterial resistance in the PICU. The implementation of the antibiotics guideline appeared to be effective.