This study investigated plasma and bone concentrations of moxifloxacin following a single intravenous dose of 400mg to consider its potential role in the treatment of osteomyelitis. Eight patients who underwent routine cardiopulmonary bypass surgery were enrolled in the study. Plasma and bone samples were collected 2h and 5h after the end of infusion. High performance liquid chromatography was used for the determination of moxifloxacin concentrations. Mean plasma concentrations were 3.36 microg/mL and 2.93 microg/mL at 2h and 5h after the end of infusion. The concentrations in the body and manubrium of the sternal bone were 1.65 microg/g and 1.64 microg/g at 2h and 1.4 microg/g and 1.45 microg/g at 5h, respectively. Moxifloxacin showed good penetration into bone and could be considered for the treatment of osteomyelitis.