The fluoroquinolones are new, broad-spectrum, bactericidal antimicrobial agents structurally related to nalidixic acid. They are well absorbed after oral administration, with serum and tissue levels generally in excess of the minimal inhibitory concentrations for susceptible organisms. Their spectrum of activity includes serious pediatric pathogens such as Haemophilus influenzae, Pseudomonas aeruginosa, and methicillin-resistant Staphylococcus aureus. The potential uses of fluoroquinolones in pediatric diseases include acute and chronic pulmonary infections in children with cystic fibrosis, methicillin-resistant staphylococcal infections, meningitis with resistant bacteria, and prophylaxis in leukemic and immunocompromised children. The toxicity of some quinolone derivatives that involve developing cartilage in sensitive animal species has to be studied further. Clinical trials of fluoroquinolones from Europe and the United States in children show no cartilage or joint toxicity. For the time being and until more clinical experience with fluoroquinolones in children is obtained, their use should be limited to specific cases of therapeutic failure or multiple resistance to other antibiotics.