Since convulsions associated with the concurrent administration of enoxacin and fenbufen were reported in 1986, the concurrent administration of quinolones and anti-inflammatory drugs has been regulated to be contraindicated or carefully administered. However, the real incidence of the co-administration is not clear. We surveyed the incidence of co-administration of these drugs from the prescriptions in a community hospital. Quinolones were prescribed in 1% of the out-patients, and anti-inflammatory drugs were co-administrated in 16% of quinolone-prescribed patients. Among quinolones prescribed, levofloxacin was used most frequently. And acetaminphen (including acetaminophen-combination) was most frequently prescribed with quinolones, and anti-inflammatory drugs, which is regulated to be carefully administrated with quinolones, were frequently co-prescribed. In medical practice, quinolones were revealed to be co-administered with anti-inflammatory drugs. Since our recent report suggests that each quinolone and each anti-inflammatory drug has different activity in their drug interaction, it should be necessary to recognize the interaction of these drugs separately for their effective and safe use in clinical field.