OBJECTIVE:To evaluate the rational use of antimicrobials in 160 cases undergoing orthopaedic operations.MET_HODS:To analyse and evaluate the use of antimicrobials in 160 cases undergoing orthopaedic operations in 1999 in respect to the cost of antimicrobials related cost ratio,usage,clinical efficacy,and adverse drug reactions.RESULTS:The cost of antimicrobials per person()was 1 676.55 yuans and average day of treatment()was (7.3?3.4)d.151 patients healed by first intension.9 patients recovered in delayed healing.The ratio of the total cost,cost of drugs and cost of antimicrobials was 1∶0.38∶0.14.CONCLUSION:The use of the antimicrobials in 160 cases undergoing orthopaedic operations was reasonable.