Study aim: The comparison of vancomycin with linezolid regarding the effectiveness and cost in the treatment of diabetic foot osteomyelitis Design: Two arm parallel group randomized controlled clinical trial. Block randomization will be used for randomization. Settings and conduct: This study will be a randomized and controlled clinical trial. Patients are selected from different departments of Al-Zahra Hospital in Isfahan. Adults with diabetic foot osteomyelitis are evaluated for inclusion in the study. Participants/Inclusion and exclusion criteria: Age over 18 years old; hospitalization; diagnosing chronic diabetic foot osteomyelitis based on the presence of pain or tenderness or a sinus with purulent discharge in the area; evidence of osteomyelitis in bone imaging (radiography or MRI) and serum CRP level being higher than the maximum normal value Intervention groups: Intervention group: linezolid (600 mg IV or PO q12h) + meropenem (1 g IV q8h). Control group: vancomycin (1 g IV q12h) + meropenem (1 g IV q8h) Main outcome variables: Clinical response (improvement or failure)