The activity of enoxacin, a new quinolone carboxylic acid, was evaluated against 3014 clinical isolates of Enterobacteriaceae, Pseudomonas and other non-fermenters and Staphylococcus aureus. Comparison was made with gentamicin, tobramycin, amikacin, netilmicin, ampicillin, piperacillin, carbenicillin, ticarcillin, ticarcillin plus clavulanic acid, trimethoprim, cotrimoxazole and erythromycin. In general enoxacin was the most active compound and resistance was only rarely encountered