The records of 84 patients with bone infections treated with high-dose levofloxacin (i.e. 0.75-1g daily) for more than 4 weeks were reviewed. Patients were given either 500 mg b.i.d. throughout the treatment period [Group 1 (n=41)], 500 mg b.i.d. for 3 weeks and then 750 mg q.d. [Group 2 (n=21)] or 750 mg q.d. for the whole treatment period [Group 3 (n=22)]. All patients had combined therapy, including levofloxacin-rifampin in 62 cases (73.8%), for an average duration of 13.7 weeks. Muscular pain and/or tendonitis were reported in 19 patients (22.6%) which affected more patients in Groups 1 and 2 than in Group 3 (14/41 and 5/21 vs. 0/22; p=0.01 and 0.001, respectively). A dosage of 750 mg q.d. may be warranted for prolonged high-dose levofloxacin treatment in patients with bone infections rather than 500 mg b.i.d. for the entire duration of treatment, or for the first 3 weeks.