AIM: To determine whether an association exists between ciprofloxacin and faropenem resistance in bacteria including multiply drug-resistant isolates. METHODS: The MICs were determined for 150 fluoroquinolone-resistant bacteria, plus 20 nalidixic acid-resistant strains of Salmonella enterica serovar Typhimurium. RESULTS: Faropenem was very active against Escherichia coli and Streptococcus pneumoniae, but 5/31 Staphylococcus aureus and 2/26 Bacteroides fragilis required > or =16 mg/L for inhibition. Of 30 multiply drug-resistant isolates with a phenotype suggestive of enhanced efflux, only for one strain (a Bacteroides fragilis) was the faropenem MIC higher than that associated with the other isolates of the same species. CONCLUSIONS: Faropenem was in general as active as imipenem. There was no association between resistance to ciprofloxacin and faropenem or imipenem resistance.