Abstract: The invention concerns organic chemistry and, more precisely, therapeutic chemistry. It describes specifically novel 6-fluoro 7-piperdinyl quinolone-3 carboxylic acids having general formula (I) ##STR1## in which Z is an amino radical, and R1 is a radical (lower optionally hydroxylated alkyl), an acyl radical derived from a carboxylic organic acid, from an alkyl carbonic acid, or from an alkylsulfonic acid, or a carbonyl arylamino radical having formula (II) ##STR2## in which Ar is a mono or bicyclic aromatic radical, optionally substituted by one, two or three substituents selected form lower alkyls, halogens and trifluoromethyl; and X is oxygen or sulphur. The invention also concerns the addition salts of said acids. The compounds of general formula (I) constitute the active ingredients of antibacterial drugs.