Ofloxacin can cause retarded ossification and arthropathy in young animals, but there is no published information about its teratogenicity in humans. A 36-year-old woman was treated with ofloxacin 200 mg bid for 6 days during the 19th week of gestation. Ultrasound follow-up of the measurements and structure of the fetal long bones revealed no abnormalities. The neonate's physical examination and X-rays of the chest and long bones were normal. Although no teratogenic or toxic effects were observed in this patient, the use of ofloxacin in human pregnancy should only be a clinical consideration until sufficient evidence regarding its safety in the human fetus has been published.