Abstract: Liposome-encapsulated quinolones and specifically liposome-encapsulated ciprofloxacin dramatically enhances macrophage functions, induces NO production and augments the production of cytokines, rendering the composition an immunoprophylactic and immunotherapeutic agent with unique clinical potential. Liposome-encapsulated ciprofloxacin and other quinolones could be extremely useful in antimicrobial, anticancer and AIDS therapies. In such cases, the immunological status of the patient is often compromised or suppressed, making them susceptible to microbial infections and to the development of tumor growth. Selective augmentation of cellular immunity by activation of the microbicidal and tumoricidal activities of macrophages, induction of NO and cytokine production could be of primary importance to such patients in terms of protecting them against microbial infections and inducing their cellular host defense to tumor cells.