series of 7-[3-(1-aminoalkyl and 1-aminocycloalkyl)-1-pyrrolidinyl] quinolones have been prepared and their biological properties evaluated. Among them, 1-(S)-aminoalkyl derivatives exhibited potentantibacterialactivities against gram-positive and gram-negative organisms. They had moderate lipophilicity and high aqueous solubility compared to their aminomethyl counterparts; e.g., the 3-(1-aminoethyl)-1-pyrrolidinyl